Golf Mk3 - tail lights pulsing

[herby0001]

Hi folks,

VW Golk 1.6CL, 1993 L-reg, engine code ABU.

Got a niggle, well, perhaps a warning of worse to come. When the lights are switched on (be it side or main lights) and the indicators are used, the red tail lights pulse - ie. when the indicator bulb is lit, the tail lights on both sides dim - when it goes out, normal brightness is restored. And so it goes on, pulsing. Inside the car, whilst indicating, braking or reversing, the indicator lamp for the rear foglight (by the headlight switch) goes on and off. This occurs when the engine is idling and reving.

I thought it's an earthing problem and have located the earth point near the NSR cluster, but that is sound. Is there anything obvious I am missing? Any known issues? I wouldn't want it to degenerate into a Ford Escort Mk3 with dodgy electrics that flashes away like a christmas tree!

Any thoughts on this appreciated!
Thanks,
Herby.

[bora(ing) nick]

It DOES sound like a dodgey earth.....

Does fog lamp indicator come on and stay on when in reverse, and stay on when the brake is pressed (as your brake lights would/do)???

You may of damaged the wiring to to lights.... Check the wiring from the boot forward.

Also keep an eye open for water ingress / damage. This could cause similar effects without blowing the fuse.

Let us know how you get on....

Nick

[herby0001]

Does fog lamp indicator come on and stay on when in reverse, and stay on when the brake is pressed (as your brake lights would/do)???

Thanks for the tips Nick. I'll trace the cabling from the rear and see what I can find!

Yes, the fog light indicator does stay on when in reverse and also when the brake pedal is depressed.

I'll post back once I can get a dry day during a weekend. Cheers.

[passat boy]

the tail lights always leak through their seals and not always visible.remove the light cluster(holding bulbs in boot)disconect the socket remove bulbs and inspect allover for white colouring(corrosion).clean by light sanding with water paper and wd40 spray on the surfaces.clean the bulbs gently and the wiring connector can do with a wiff of wd40 if clean otherwise clean them out(disconect the battery and remember radio code if applicable)seal taillights with black car sealent lightly applied after cleaning all surfaces properly.look into your light cluster for traces of water to confirm leaks also.

[herby0001]

...clean the bulbs gently and the wiring connector can do with a wiff of wd40 if clean otherwise clean them out...

Update: the problem was traced to the lower connector on the NSR cluster. One of the pins on the cluster had a fair amount of white corrosion on it. Cleaned it all off as much as I could and also from the conenctor and the problem is sorted! Thanks to all contributors. You're all a great source of knowledge! Thank you!

[bora(ing) nick]

It's good to see someone posting after the problem has been resolved.

More often than not, people don't let you know what the cause of the problem was, resulting in threads being repeated again and again.

Glad to see your escort has been fixed!!!

Nick