Jump to content
Click here if you are having website access problems ×

FIA cut off key


TomB

Recommended Posts

Hi,

For a number of years Ive had a feature of my FIA switch that it doesn’t kill the light and dash lights. It kills everything else, but not the lights. I’ve got my scuttle off at the moment so I thought I’d try and investigate why.

The car is an early 1996 K series, before the comprehensive changes to chassis and loom post 1996. As such, it has an older Ford chassis wiring, but with the injection engine loom.  

My Multimeter shows battery power is reaching the light switch (brown & blue wire) when the FIA switch is off and the wiring diagram suggests this is from a common connection on the ignition barrel with the brown wire that eventually ends up at the starter solenoid. As such at the solenoid, it’s sharing a big red cable.

On Sevens with Ford chassis wiring, how do I make sure the FIA kills all electrics? 

Below are the diagrams I’m working with. 

AAEF3467-BF27-493C-843F-FBCB22DFE39B.jpeg.1189a0499d37a3a4e7274317a6b0d568.jpeg

 

Below, the red is from the battery, green is to the ignition and blue is to the light switch. The cut off key doesn’t appear to cut thes connections, as neither go to the small connection on the switch.

ACD6DF5F-0BE5-409F-9EA7-E396420E42C6.jpeg.af1c9f229645b9441ab4e7158185564a.jpeg

 

Is thish  just something I have to accept, or is there anything I can do.

 

 

Link to comment
Share on other sites

As your diagram suggests, the fat red battery +ve lead should go directly to the FIA switch.  Another fat red cable should run from the FIA switch to the starter solenoid, feeding the starter and all other circuits.  

Are there any extra wires/circuits connected either to the battery +ve terminal, or to the battery side of the FIA switch?

JV

Link to comment
Share on other sites

When I first built mine the instructions for the FIA switch were a bit vague. Two semi thick red wires would only reach the battery so thats where I connected them. After some research I lengthened it and connected to the post on the starter motor which is where the mega thick cable from the FIA terminated. It has the alternator feed (brown), main loom feed (double red)and thick red cable to FIA terminated at the starter. The other thick cable from the FIA goes to battery +ve.

Funnily, the alternator feed wraps around the engine within the trunking but is only 8" away as the crow flies (IYSWIM)

8882FAA6-7A3A-44F6-9F13-44D7BE249DF8.thumb.jpeg.184c78cc2ef42bbf5cd12da4420ac8c8.jpeg

Link to comment
Share on other sites

Hi John, on the positive battery terminal I’ve got a big red cable, a small brown I fitted for the relay modification which goes to the new rest under the ECU, and another large connector which I presume is the main feed into the loom.

D68A1FBC-1E5E-4338-84DA-326B6BD2271E.jpeg.b56e1a6075e5eee2459f30c082d71496.jpeg

Link to comment
Share on other sites

Thanks John, that’s the conclusion I seem to heading towards. The other connection to the positive side of the battery heads off and enters the loom near the injector rail. So is this non standard? The picture of the wiring diagram I originally posted has the red line heading to a union of several brown cables, from which item 56 starter solenoid is supplied from. Also from this union are the brown wires to the ignition barrel.  So the wire to the solenoid is coincident , and not part of the story. 

Leave me with the remaining question now I think I’ve figured it out - how do I fully kill the electrics with the FIA switch! 

Link to comment
Share on other sites

...how do I fully kill the electrics with the FIA switch

If everything is working OK at the moment (except the full FIA-switch function, that is), you can ignore the wiring diagram.  All you need to do is to move the extra wires that are attached to the battery +ve to somewhere downstream of the FIA switch.  I'm not familiar with the earlier chassis loom you have, but the obvious place would be the starter solenoid post.  Failing that, you could use the "output" terminal of the FIA switch itself if the wires are long enough.   Or you could adopt Wrightpayne's idea in #4 and fit a dedicated positive terminal post. 

JV

Link to comment
Share on other sites

I’ve investigated the additional connection to the battery and it’s made it up of medium sized twin brown cables crimped into a battery terminal. They head off into the loom under on the right side of the car near the pedal box, so this live feed is not connected to the FIA key. I can only suppose this is quirk of having a K series in an pre-96 chassis, before the post 96 chassis and wiring changes for the K series. If I lengthened the wiring and took it to the starter as suggested by John, the FIA would kill this feed. 

Ill have to look back through my old pictures and see if it’s always been like that. 

Link to comment
Share on other sites

It looks as though your FIA switch was not a factory-fitted option but added later.

The 1996 Assembly Guide states (for a car not supplied with the FIA switch):

14.4 Electrical Connections

viii) Connect the brown/red lead to the outer threaded stud on the starter solenoid, this cable is protected by a black ribbed sheath.

x) The two brown leads with the 8mm terminal at the rear of the engine must be connected to the positive terminal on the battery along with the main battery lead. (beware these wires have a black sleeve.)

It then adds the following under Optional Extras:

18.10 Battery Master Switch [aka FIA switch]

d) Remove the existing battery to starter solenoid cable (red) completely though it is reused later.

e) Disconnect the two brown wires from the positive terminal of the battery, cut off their terminals and join the bare wires together.  Solder to this joint the additional brown wire provided insulating well with insulating tape, and attach the 1/2" ring terminal to the other end.

f)  This new wire is routed along the chassis tube above the gearbox, up through the wiring loom grommet in the transmission tunnel cover and then behind the dashboard to the switch, connecting it to either of the main [FIA switch] terminals.

g) Attach the new red main battery cable to the starter solenoid and following the chassis members, run this above the gearbox, through the wiring grommet and along to the switch attaching it to the same terminal as the brown wire.  

 

So, it appears that, when your FIA switch was fitted, your double-brown lead should have been transferred from the battery +ve to the switch.  I think if you do that (and move your extra relay wire there as well), you'll have a fully functioning FIA switch.

JV

Link to comment
Share on other sites

Thanks John, your confirming what I worked out this morning. The install has missed extending the two brown wires from the battery. I’m in the process of trying to solder them together and extend the brown wire to the FIA key. My soldering skills are somewhere between Stevie Winders and Blind Pew, so it’s taking a couple for attempts, but I’ll get there! 

Id forgotten about the relay positive feed, does that need moving too? As it’s currently set up, the relay will have permanent supply. Does that matter? 

Link to comment
Share on other sites

  • 6 months later...

Glad to hear I am not the only one with a wrongly fitted FIA switch in a K-series ... and so doesn't cut any of the circuits other than the engine loom... 

So starting from the same setup as @TomB (three brown wires directly connected to battery +ve), I need to "extend" these with a suitable wire to the either solenoid or FIA switch. My question is what current rating should this extension be...? Amongst other things it feeds fuses 11,12 and 14, which add to 60 amps... but a 70 amp wire seems a bit excessive.... I can't find any guidance on here for those who didn't get a piece of brown wire with their BMS kit... !

Link to comment
Share on other sites

Instead of soldering (which I’m awful at), I extended both wires to the cut off switch using good crimping pliers, terminals and heat shrink. I used the 30amp heavy duty cable from Halfords. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...