Better rear lights project

**DISCLAIMER** - I have no automotive qualifications. This blog is a record of my actions, not a list of instructions. You cut into your wiring looms and mess with safety-critical components entirely at your own risk.

As ARs, we find ourselves leading more blats than many people. As such, various members have on occasion mentioned that our rear lights (the standard Caterham caravan lights) can be difficult to see clearly in certain conditions and at some specific times of day.

Unfortunately those conditions appear to include bright and clear days, overcast days, changable days, low light, fog, rain and light mist; and the times are specifically when the sun is low in the sky, high overhead, below the horizon, or at some point in between.

In short, the standard lights are a bit crap.

Various iterations have been tried, from the standard red/orange cluster lenses with clear filament bulbs, clear lenses with amber indicators and red LED stop/tails, bigger and brighter LED stop/tails, silvered plastic reflectors within the clusters, silver reflective vinyl in the clusters, etc. - all to no particular avail.

So, the search was on for some significantly better rear lights, that either looked similar to the originals or, if different, different in a good way.

There's various rectangular LED lights, panels and clusters out there from various suppliers (carbuildersolutions, SVC, eBay etc) but I personally felt that none of the "nearly but not quite the same shape" rectangular options were quite right, somehow. Not close enough to be a direct replacement, but not different enough to look like anything more than a poor attempt at a copy. It's hard to describe but for whatever reason, none appealed.

Eventually I found some interesting looking units on (formerly Seven Speed) based around a 95mm round light unit form.

**EDIT** Sadly, kit Car Supplies has since ceased trading, it appears. I can still find the light units and housing on Car Builder Solutions, and what appears to be the same reflector (albeit at a higher price) on Leisure Shop Direct. Links modified to suit:

This form factor of 95mm light is available from various sources and in various configurations (i.e. just an indicator, just a stop/tail, a reverse/fog unit, etc) so I thought quite a while about these choices.

The above housing has no integral reflector, so the options there were to use one slot in each housing for the matching reflector, or to have a different reflector elsewhere which would free up both slots for lights (at the expense of having more holes elsewhere for reflectors which might look a bit bodged). I've always prefered indicators to be separated from tail lights in general, but pictures of the above setup looked better than I imagined twin lights with a different reflector elsewhere might, so I settled on the list above.

Total spend was to be just about £245:

  • 1x LED flasher relay at £14.99 NB. See later posts for the trials of getting a working flasher unit...;
  • 2x LED Bullseye Rear Light Unit - Red/Amber Lens at £69.99 each;
  • 2x Shotgun Rear Light Housing - Caterham at £29.99 each;
  • 2x 95mm Reflector at £9.99 each;
  • Shipping at £9.99

I asked Carl Van Baars (Seven Speed / Kit Car Supplies proprietor) for his opinions on the brightness of the lights, on the EU-approved scale of "Are they on?", through "Standard Caterham" and "Visible", up to "Ow my eyes" and finally "New Audi". £245 is a lot of cash to commit to a project without some idea it'll be worthwhile, after all.

Carl was good enough to phone me back for a chat, before pointing me at a video clip online of the lights on the back of his car. To be honest I watched the clip (a donut at Mulsanne) a few times before I remembered to look for the lights disappearing into the distance, but all in all this was enough to convince me - apart from anything else, amongst the vast array of lights available, these are the lights Carl chose to fit to his own beloved Seven - and the order was placed.

Note the housing is available in two versions, with a curved back to fit a Caterham arch or a flat angled back to fit a W*******d - make sure you pick the right option!

Next, sit back and wait for them to arrive...


Oh, that YouTube clip:

I should also point out, I have no connection to Carl or any of the companies mentioned above other than as a customer / potential customer.

Ooh, do we get a signature? Smile

So, they arrived...

First thoughts:

1. Everything looks like it's good quality kit. Excellent! Smile

2. "Why are the housings so deep??"

The shotgun housings are 60mm deep at the bottom and 80mm deep at the top, due to the curved taper on the mounting face of course, whilst the light units are closer to 20mm only. They look massively larger than they need to be, however they're pretty light so trimming 30mm off the mould wouldn't save a much in the way of grams.

3. "The leads on the lights are quite short"

Yes they are, at about 6" or so (150mm ish). They certainly aren't going to reach all the way from the installed location, across the inside of the rear arch, through the side skin, and to where the relevant econoseal connector is going to be.

4. There's no fitting hardware - you'll need some self-tapping screws to mount the lights and reflectors to the shotgun housing, plus your pick of screws or blots to attach the housings to the rear arched. Obviously you may have no shortage of suitable spare screws and bolts available but if not it's a minor annoyance to then have to go to your hardware retailer or wait for an online delivery.

Each housing has four plain holes and four with hexagonal indents to hold an M5 nut (or imperial equivalent no doubt) captive, so plenty of options there.

5. While the bullseye lights come with little red plastic inserts to clip in and hide the mounting screws, the reflectors do not. Ho hum, I guess that's just what the manufacturers do and don't include (I suspect the lights and reflectors are from different manufacturers). 


As it turns out, (2) is looking like a positive thing, rather than a negative. All that empty space is (I think...) going to be large enough to also accomodate an additional econoseal connector. Given the current cables from the existing cables to the old fitting won't quite reach either, and are quite grotty due to ten years of water ingress to the rear clusters, and I'm not keen on solder joints in cables anyway, my plan is:

- Fit an econoseal plug to the light units;
- Make up an extension lead such that one connector is contained in the housing, the cables of this will then run to the connector within the sideskin. I'm pretty sure a 4-way econoseal will (just) fit in the housing. Watch this space...

This should remove the need for any soldering of old and new wires and make fitting everything easier too - so (3) isn't actually a negative either.

Also, when you line the housings up against the caravan lights, the footprint is actually pretty similar and the overall projection from the rear arch isn't much different either, when compared to the rubber block plus lenses.


They're going on an SV, with a windscreen, two occupants, a spare wheel, a jack and assorted tools on board. I'm really not too fussed whether they save or add 50 grams, although the former would obviously be better. Also I have no clue as to the weight of the caravan lights (but will check this when I remove them).

That said, the three items - housing, lights unit, reflector - come in at 353 grams each side. Obviously to that will be added an econoseal connector, four small screws and four M5 nuts/bolts/washers. So, probably about 400g per side, which doesn't sound particularly massive.

353 grams without screws and connectors353g without screws / bolts / connectors. They look nice too!

Individual piecesThe three components - deliberately taken with a flash to "prove" the reflector.

Note the housing is a shell only rather than a solid form, so if necessary you can run cables between the two voids and use the space behind the reflector e.g. to backlight it; similarly if you opted for two lights and had the reflector elsewhere you can get away with a single cable hole through the rear arch.

So far, so good!


Edit: NB. these really are circular - in some browsers the Blogs formatting squashes the pictures for width and therefore distorts the view.

Ooh, do we get a signature? Smile

First test

While I wait for the mounting screws, econoseal connectors, wire and heatshrink (for my planned extension cables) to arrive, I thought I'd do a "quick and dirty" test of one of the light units, just to confirm the investment of effort and cash was going to be worthwhile.

For this I removed one rear lens from the car and connected the earth wire of the new light to the earth screw clamp of the existing block.

Then, the standard bulb holders have a slot in them through which a wire can be fed, then trapped against the positive pin in the holder by re-inserting the bulb.

Best do this with the FIA key removed / battery disconnected, just in case you short something out...

Then, FIA key back in and flick the relevant switch.

All of these pictures were taken at the carefully-measured, VOSA-mandated distance of Several Paces From The Back Of The Car, under the EU-approved lighting conditions of Some Time During An Overcast Afternoon, and are therefore legally approved as a perfect representation of the results.

Some or more of the above paragraph may be Wallop of Cod.

Later edit for clarity: The below pictures were taken with an aftermarket LED stop/tail in the right hand cluster. This bulb is rather brighter than a standard incandescent, as later posts will show.

Tail light and indicators on:
Tail and indicator on

Just the tail light:
Tail light

Just the brake light (wired to the tail light connection, so the right hand cluster is only the tail light):
Brake light

My patience and curiosity didn't stretch as far as every possible combination of illumination, however (as the pictures show) I'm happy that these lights are massively brighter and more attention-grabbing than the original caravan lights as fitted by the Caterham factory.

If anything the phone camera doesn't do the difference justice.

They're not "New Audi" (Carl did say they weren't), however if you're driving too close when I hit the brakes or signal a turn it's fair to say they're in the realms of "Ow my eyes".

Ooh, do we get a signature? Smile

All that empty space is (I think...) going to be large enough to also accomodate an additional econoseal connector.

Quick update, the econoseals arrived this morning and they're smaller in real life than they were in my head, meaning they fit into the void space behind the light units with masses of space to spare. It's not even going to be a squeeze.


I now have *almost* everything I need to fit these things, just waiting on some bolts to hold them to the car. Patience...

Ooh, do we get a signature? Smile

I started making up the econoseal connectors today, and fairly soon ran into a RTFM moment. Whilst being an inquisitive fool the other day, I'd plugged a couple of the yellow plates into the housings, guessing that this was the right way and that you'd then insert the pins later, which would then somehow latch into place.

Er... no.

The correct order, as most of you will probably now be laughing about, is to insert the pins (or sockets) FIRST, and THEN fit the yellow plates. Or as they're otherwise known, the locking plates. The clue's in the name, really...


Did I mention that once the locking plates are fitted to the plugs, you can't remove / reuse them?

Ah well, lesson learned, and a couple of new econoseal connectors bought. Eejit.

Moving swiftly along (that line above? that's drawn under the RTFM affair, that is), this next bit involved getting under the car's back end to reach the connector that's just inboard of the sideskin. This is so I could disconnect it, and plug one of the new lights in to discover the wire colour mappings, which obviously (!) differ between the light and the Caterham wiring loom.

Note that the space between the side skin and the fuel tank is about big enough to accept precisely one of my Imperial Standard hands, which is only about half as many as you need to disconnect an econoseal. You also have very little chance of being able to see what that hand is doing at the same time, because your view is rather obscured by... a hand.

So, take a good look, figure out where the socket half is sitting and especially where the release lever is. Now, stick your prefered hand in the gap and feel your way to being able to press the release lever. Push the whole collector as close to the sideskin as it will go. With your other hand, grab the wires where they come out through the grommet in the sideskin. You should now be able to (carefully) demount the connector.

With a bit of luck you've been fiddling with the correct connector and haven't now mistakenly disconnected the nearby 2-way connector for the reverse or fog light (depending on side).

With a bit more luck, assuming the loom wires aren't zip-tied to the chassis too close to the connector, the socket will drop far enough to be visible without lying underneath the car. 

Next, I fitted the econoseal pins to the light unit so as to be able to plug them into the socket. I also enlisted MrsH to push the brake pedal, although with only four wires (earth, indicator, tail, stop), once you have three of them figured, you can reasonably safely guess at where the last one goes...

The caveat here is that my wiring loom may not be the same as yours, depending on age of car and who's done what to it since it was new.

That said, this was correct on my car:

WireCar loomLight Unit
StopThe other one...*Red

*Sorry, I didn't note these colours at the time, just from the picture I took (above). See prior comment about getting three out of four correct.

I have now fitted plugs to both lights, in the assumption the connectors on both sides will be the same (risky, I know!), so the next step is to check both lights on both sides, before (when the new connectors arrive... Censored ) making up the extensions and getting on with actually fitting everything.

Later edit: The wiring diagram claims the indicator cores should be Green+White for the right hand indicator, and Green+Red for the left. Apparently no-one told my car...

Ooh, do we get a signature? Smile

Today's good news:

I wired the econoseal plugs on both lights correctly, and the loom connections are also the same on both sides of the car. All the right bits light up when their respective switches are operated. Hurrah!

Today's "things we have learned":

On the right hand side of the car, all that stuff about getting one hand up inside the side skin to the econoseal plug? Ha! No chance!

The fuel tank breather / overflow (?) / whatever pipe is in that gap, forget it.

Instead, stick your head under the wheel arch and remove the grot-encrusted grommet around the wires as they come through the sideskin. Then wiggle the whole connector block out through the gap - it does fit, just - and disconnect. Keep hold of the socket part until you plug something else into it, for fear of it springing back through the hole and out of easy reach.

Today's bad news:

The flasher unit bought originally failed the other day; so has the replacement which arrived this morning.


Their description says "LED flasher relay 12volt will operate LED indicator lights and conventional bulbs or a mix of both". I have no doubt Carl copied this information from the manufacturer blurb in good faith, however something is clearly amiss.


You switch the indicators on (via either the direction indicator or hazard warning swithches), and nothing happens for a second or three - certainly long enough for you to think it's a dud.

Then, it starts flashing, just fine. If you weren't in the middle of a light replacement project necessitating lots of testing, this would likely be enough for you to believe the unit worked fine. Probably enough for you to get out the end of the road and away onto a blat, too.

However, after about 20-30 flashes, either in one go or across multiple tests, the indicator lights and whatever audible tell-tale you have just stay on permanently.

I read elsewhere online a suggestion that some flasher units are "LED only" and will "self destruct" if used with standard bulbs; my first suspicion was that Carl had been sent a dodgy or under-specced batch.

I should point out that when the first one died, I emailed Carl and he put a replacement unit in the post immidiately, first class, no questions asked and no request for a return of the faulty unit, so absolutely no complaints there. Currently though, this single, small, relatively inexpensive, component is preventing the completion of the project.


Edit for update: I emailed Carl again and he phoned me directly back (again - excellent service!). He's passing on my double issue to the (very reputable, mainstream) manufacturer and we had some brainstorming about the possible causal issue.

Without wanting to prejudice anything, and having gone through all the things I've done / not done so far, and the rest of the setup (including, the regular flasher working the standard bulbs, no fuses blowing, etc) it occurred that the car is connected to its battery conditioner when not in use.

One possible theory we have then, is that the electronic flasher unit is someone getting 'killed' by the conditioner's output. I have no idea how or why this may be the case, but currently (no pun intended) we've got nothing better, until the manufacturers respond.

Ooh, do we get a signature? Smile

More progress on Sunday... Still awaiting the manufacturer response on the flasher unit, but as I envisage that being sorted before the next chance to take the car out, I decided to press on regardless.

First step was to figure how big a hole is required to feed an econoseal plug through the arch (as the hole needs to move from the original) - I think you could get it through a 22mm hole, but I picked 25mm to give a bit more space and the availability of suitable blank rubber grommets.

Then, with a sample grommet and a test piece of cable (four cores bundled with 6mm heat shrink), I used Mrs H's crafting hole cutter / punch thingy to determine that a 4.5mm hole was ideal.

Next, figure out the length required for the extension leads, so some grubbing around under the rear arches was called for. At this point I found that the grommet where the cables come through the sideskin on the nearside was trapped by the rear arch itself - er... not sure how this works, in my head the arch would have to be attached before you put the wiring in. I guess the builder did some slackening of bolts!

See? Grommet, trapped behind the inner flange of the rear arch.

A wheel removal and a few seconds with the dremmel sorted that, and who doesn't love the smell of burning fibreglass in the morning? I then refitted the wheel, which, as it turns out, was a mistake.

Some fumbling later (and I confess, revising my findings later in the process) left me with a length of 370mm between the connectors, albeit based on something of a guess as to where the new light units would fit. They could probably, I later found, be a little shorter still, but, better that than not being long enough!

Making up the socket first, I then added the 25mm grommet and heat shrink, then (after removing the old lights) the re-used sideskin grommet and the plug.

First extension lead complete, barring a tiny bit of heat shrink needing the heat gun.

Removing the old lights is simple enough, four big screws and a bit of a heave because the rubber block was stuck to the arch after ten years. It was also half full of mud, thanks to the "drain" holes at the top...

Ew! Luckily it all washed off...

Picking the location of the new housing was mostly definied by a need to hide all the existing holes - the car will get new arches later in the year when she's resprayed, so I didn't feel the need to go patching things. The old hole also accepted a 25mm blank grommet nicely, to prevent the new fittings getting filled with spray from the rear wheels.

Incredibly at this point I notice I *don't* have a picture of the new unit on the first arch... how remiss. However, the process is simple enough - figure out where it's going, make sure it's level etc, hold it firmly, mark the new holes for mounting it, drill holes. The new housings have 8 mount holes in total, four "just holes" and four with hex recesses that hold an M5 nut. I choose to use these and fitted them with M5x16 bolts, with large washers, fed from within the arch and with nyloc nuts in the light housing.

I've also used a plastic P-clip on one of these, to hold the cable snug to the arch and well away from the rear wheel, and used IVA trim on the rear edge of the housing to give a good fit against the arch, because the profile doesn't match my arch shapes precisely at the height I had to fit them.

Having got the housing roughly in place but before final fixing, it was time to drill the new 25mm hole in the arch, to feed the cables through.

I'd just started doing this, with a long spade drill, when it occurred that removing the wheel again might be prudent - popping the spade drill through the arch and straight into the tyre woud be an expensive mistake...

Be *very* careful with the spade drill, it would be easy enough to do more damage than you wanted to the arch. Once the hole was done, I also used a round file to get in and chamfer the inner face of the arch, to make the hole edge a bit thinner for a better fit of the grommet.

Then it's just a case of feeding the cables through, seating the grommets, tightening the mounting bolts, then finally fitting the light and reflector to the housing, using 6BA self-tapping screws. Careful not to overtighten these!!

Amazingly, it all worked, first time! Pictures to follow...

Ooh, do we get a signature? Smile

Oh, a word on weights: I'm not a weight weenie, as mentioned (much) earlier, but for the record, for the nearside lights only at this time:

Weight of original lights, rubber block, cables etc removed from car: 628g

Weight of everything added to car: 441g

So that's a saving of nearly 190 grams per side, so about 380g in total.

So, it's not quite as much weight saving as swapping the rubber blocks for carbon ones, but this way you get better lights at the same time...


Ooh, do we get a signature? Smile

So, I took some comparison shots in the dark last night; I'll get to them shortly but as you might imagine, any point of light is reasonably noticable in the dark of a winter evening.

However, here's a few from this lunchtime. Bear in mind even here, the car is in an unlit garage in a 'valley' between two houses that butt up to the drive, so there's not as much ambient light as there may be.

So, here's the new tail lights vs a 60-LED (red) stop/tail bulb from, in the (clean) factory Caterham red/orange cluster:

The new lights are clearly brighter and more noticable than the LED upgrade bulb in the old cluster. I think it's more noticable to the naked eye, but my head is also no doubt biased to wanting the new lights I've spent money on to be better.

Then, mostly for amusement, I put a standard twin-filament stop/tail bulb back in the old cluster. This is what most of us are driving around with, I guess, so if that's you, this is something like the "benefit" that running with your lights on during the day provides for following traffic:

Are they on??

Obviously in normal daylight, the car should be plenty visible, but imagine there's a light mist, or a bit of rain or spray, or it's just a grotty day - all those daytime conditions where you'd put your lights on "to increase your visibility".

Yeah, good luck with that...

Here's a picture from closer up with a bit more light reflected off the car itself:

The incandescent bulb lights up just enough to see there's a bulb fitted, but not a lot more.

It's only when you make the effort to look at your own tail lights that you realise just how terrible they are.

Note also, the 60-chip LEDs from ABD were not E-marked when I bought mine (they may now be, I don't know), neither are the LEDs Caterham sell (which, in terms of brightness, sit somewhere between the two bulb types above), so in the event of a shunt, a very picky insurer could potentially claim your rear lights were "defective" despite being better than the incandescents.

The new light fittings are suitably E-marked and thus fully road legal.

Ooh, do we get a signature? Smile

A couple of pictures from last night...

Just the tail lights:

I forget which bulb was in the old cluster at this point, I think the 60-chip LED bulb. Note the much bigger halo the phone has recorded around the new light.

Brake and tail:

The new light is so bright it's caused a ghost image in the picture, above the old lights. This picture is cropped so you'll have to take my word on there not being an equivalent ghost image of the old light.

Ooh, do we get a signature? Smile

A couple more pictures:

Inside the nearside arch, showing the four mounting bolts, new grommet, P-clip to retain the cable, and the old screw holes and old cable hole.

I just realised I should plug those old screw holes, so some epoxy putty will be called for. It's only going to be a rough bodge of course, as they're not visible from the outside and the arches will be replaced shortly anyway.

And on the offside:

Sideskin grommet removed and connector pulled through. Due to the noted difficulty of getting a hand inside the sideskin this side, thanks to the fuel tank breather, I figured that zip-tying the socket to the suspension to prevent it springing back through the hole would be a sensible precaution!

Ooh, do we get a signature? Smile

Everything's now fitted! Almost hurrah...

Drilling the cable hole in the offside wing went a little awry as the spade drill started to wobble and made a slightly-less-than-circular hole. Grumpy

It seems the same happened with the original build too, given the old cable hole this side was closer to 32mm than 25mm - luckily I had some 32mm blank grommets so a couple of moments with a file enabled me to fit one of these.

Also, despite spending *ages* ensuring (or so I thought) that both housings were at the same height both sides, as soon as I finished, Mrs H took one look and asked if one fitting was slightly higher than the other...

She's right, they are. Censored

In my defence, I also had to ensure these fittings hid the old holes, and as previously mentioned the car will be getting new rear wings later this year as part of a respray, so I'm not *too* bothered by this mis-match.

Quick picture of the second housing, as partially fitted (still missing a bolt at the lower left), with the extension cable socket visible:

Just waiting on a working flasher unit.

Ooh, do we get a signature? Smile

Oh Fer.... (FS)

New flasher unit just arrived, from a reputable ebay seller.

Disconnected the conditioner, plugged the flasher in, engaged the FIA key, ignition on, hazard switch on...

Nothing. Not an electronic sausage.


Try the direction indicators...

Nope, nothing there either.

Wait... Ah! After several seconds, some flashing started:

On, off, on, off... still off... on-off-on-off, on, off... wait for it... wait... on, off... staying off, on, off, on, off, on, off... hang on while we have a think... on, off... still off... on, off, on, off... off... off... on, off, on, off...

There's no way that would pass an MOT nor be safe on the road.




I'm starting to think there's something screwy with my electronics, somehow - although I didn't think the ECU had anything to do with anything regarding indicators, I always thought it was a simple case of applying voltage to the flasher unit, which then just damn well got on with it.

Indeed, the old thermal / mechanical flasher still works fine for the hazard lights (the incandescent front and repeater bulbs providing enough load to give a reasonable flash rate). Unfortunately for direction indication, two incandescents is clearly not quite enough load and the old flasher then gives a 4Hz (approx) flash rate, where the MOT mandates a range of 1 to 2Hz (60 to 120 flashes per minute).

I'm stuck for what to try next (obviously I have contacted the eBay seller, who has sold hundreds of these units, so if anyone's seen this before I would hope they have).

Ooh, do we get a signature? Smile

Amazingly, now fixed. Don't really know how...

There was a suggestion from blatchat that the flasher unit socket wiring may be reversed, which certainly seemed plausible on a kit-built car. Certainly worth investigating.

Having found the K series wiring diagram in the 'technical guides' section of this site, where Shaun_E had uploaded them recently (thanks Shaun!) I printed the relevant one off (then did a screen grab zoomed in to the relevant area and printed it off again, somewhat larger) and we headed back out to the garage, armed with a multimeter and various torches.

After much time head-down in the passenger footwell (feet over the rollbar...) and prodding with the multimeter confirming all the wiring was in fact correct (well... it *mostly* matches the wiring diagram...), and having unplugged the flasher unit, the flasher fuse, all the relays, the hazards switch, the fog light switch (just to get its wires out of the way), sworn at most of the bits, dropped the torch, acquired a crick in my neck, attempted to read the wiring diagram whilst effectively doing a headstand and come up short on all counts, eventually I plugged it all back together in exactly the same way it was before to show Mrs H what it had been doing.

And it worked perfectly.


...but also...


I'm guessing, there was simply a slightly grotty connection somewhere that the electronics was taking against.

That doesn't explain the failure of the first two flasher units, all I can think of for those is that operating them whilst the battery conditioner was connected and active managed to fry them gently. No proof either way there though.

Ooh, do we get a signature? Smile

Hopefully, this should be the final post on this blog.

Having made the indicators work early yesterday evening, whilst the garage heater had been on for our comfort, we let it cool down again in case the fix was heat related.

Incidentally, *before* the flasher worked correctly, it was doing this (facebook link to video):

The eBay seller of this flasher was less than wholly helpful when I asked for any suggestions; I unnecessarily mentioned the word "car" in my question whilst describing the symptoms and the seller's reply was (in full):

I cannot say as its a motorcycle relay. We are a motorbike parts supplier.

I wonder what the heck he'd have said if I'd been less specific and *not* included the word "car"?

Do motorbikes have different electricity to cars?


Plus, nowhere on the item listing does it say this is a motorbike-specific relay, nor does it mention the seller is a motorbike parts supplier as opposed to a general automotive parts vendor - indeed the listing says "Please check the pin (polarity) confiq' for your vehicle". Vehicle, not bike.

Must make a note to buy elsewhere in future.

Anyway, I'm happy to report, they still worked later in the evening when the temperature had dropped again, so it was time to crack a celebratory bottle of red as a project wrap. Turned out to be this fabulous one, from Benjamin Darnault, via Naked Wines (dot com):

Yeah, on a school night too...

Ooh, do we get a signature? Smile

So much for the "last" post. Hopefully this will be, instead.


Went out for a first blat of the year the other day, a nice 200 mile round trip (just popped out for lunch, really!). The indicators worked fine for the first 160 of them.


So, we stopped briefly, replugged everything, wiggled bits, checked and rechecked the fittings, then when that all failed (but for two random flashes along the way) made a mad dash for home before the sun set, relying on hand signals and hoping other road users knew what I was doing.

The MOT has to happen in a few days, so once home it was out with the multimeter, fearing that somewhere on the car there was a cable fault or some unexpected load that had killed the flasher unit. That said, the 10A fuse was still fine, as proven by putting the old thermal/mechanical flasher back in, which still works but flashes way too rapidly.

I took the fuse and flasher unit out, then made up a short length of cable with suitable connectors on each end (should be 6mm spade connectors I suspect; what I had to had were eyelet connectors which happily are about the same overall length and width). I used this cable to connect the relevant terminals in the block where the flasher unit sits (connections 5 and 2 / 49 and 49a / 'L' and '+' terminals), before flicking the hazards switch and then, finally, connecting the multimeter (set to "20 Amps DC" mode) across the fuse terminals.

Yes, this all involves quite an amount of flexibility with your head in the passenger footwell.

Result? All six lights on (2x rear LEDs, 2x side repeater LEDs, 2x 21W incandescents at the front) draws 3.66A, so about 44W assuming a nominal 12V.

Given the lights involved, that's absolutely as expected.

The failed flasher claims, according to the printing on the side, to be good for "0.1W - 150W", i.e. it shouldn't have a problem. I suspect it's just a bit crap.

However, that triggered a memory and I went back to the "broken bits" box and fished out the failed flashers I'd originally got from Kit Car Supplies. They both say "max 30W".

Ah. So pulling 150% of their rated load through them (when the hazards are on) might well explain why they both failed then.

What it doesn't explain is how a 30W-rated flasher unit can be reasonably described as "will operate LED indicator lights and conventional bulbs or a mix of both" when a single standard indicator bulb draws 21W - in my opinion it's reasonable to assume that bulbs will be the same on both sides of the car, so if you have a mix of bulbs, chances are you'll have at least two incandescents, and will therefore be drawing at least 42W if you use the hazard lights.


Ho hum. Back to ebay and on the recommendations of two other club members, I bought one of these:

The fourth pin (not present on the original flasher) is apparently for trailer lights - in the Caterham there is an empty socket in the block, so it's not a problem or in the way.

Due to the impending MOT I paid a bit more for first class delivery, and having bought it mid-afternoon it arrived the next day (today!). It is now fitted and (so far...!) working just fine.


Ooh, do we get a signature? Smile