The Lucas Curse - ideas sought

[polainm]

Hi, it's that old chestnut again, faulty indicators. I'm normally pretty good with car electrics but this has me baffled.

The indicators suddenly stopped working completely while driving. The hazard lights work but only on three lights, the rear left indicator light does not work.

I've checked earth and live feed to the non working rear left lamp and it is all fine back to the main loom.

I have swapped out the hazard lights switch for another old one, and I can only think that BOTH hazard switches have the identical fault!

I've ordered new replacement ones, but I've never had the direction switch totally fail before. All fuses checked too.

I will soon have replaced so many parts to solve the Lucas Curse, that all that is left is the main loom...

Any ideas?

It COULD be those crappy hazard light switches, but really, both with the same fault?

Thanks for any hard learnt knowledge shared...

Matt

[OldAndrewE]

You have not mentioned checking the bulb.  If not done swap it for the other side and see what happens.  Blown filaments are not always obvious

[Jonathan Kay]

Have you got the appropriate wiring diagrams? Let me know if you need any.

Does the rear left indicator light up when you rig a good feed to it? (Crossed with Andrew's.)

The hazard light switches are unreliable, so it's not that unlikely that you've got two duff ones. They sometimes come back to life if cycled a few times.

Jonathan

[polainm]

Thanks Andrew, yes bulb OK. I can only think it's two things; two duff Hazard Light Switches with the same fault and/or faulty indicator switch. After this, it's hand signals....Matt

 

[Molecular--Bob]

Check that the indicator relay is still properly seated, not sure it would cause your symptoms, but worth checking. I had to wrap a cable tie around mine to stop it moving.

[polainm]

Thanks Bob. I actually slightly twist the tabs so they have improved connection/fit, but still no joy....M

[polainm]

It was the hazard switches. BOTH had the SAME fault. Unbelievable....I have now ordered 3 new hazard switches, and carry one spare sealed in the car.

 

[SM25T]

Usually corrosion on the internal contacts, through lack of use. Normally remedied by switching the rocker on and off with a heavy hand a few times to clean the contacts.

[Jonathan Kay]

This post explains the interaction between the hazard warning light switch and the indicators.

And as soon as I can find a very clever improvement to the circuit that's somewhere in the archives I'll add that.

Jonathan

[polainm]

Thanks to Revilla for the wiring diagram. What really stumped me was coming to the conclusion that the hazard switch contacts had gone AWOL and swapping that switch out for another I had lying around, which produced exactly the same fault! I then went sluthing for all kinds of other problems....lesson learnt; don't leave old dodgy crap Lucas parts lying around!

[Jonathan Kay]

And the circuit modification that eliminates buzzing.

Jonathan