Losing dash lights and tail lights!

Hi, amigos!

I keep losing my dash lights and tail lights when I'm driving my 1988 Golf Cabrio (from california) 1.8GL (k-jet, JH engine).

Its usually easy to get the lights back, just knock on the dashboard or work the instruments-light dimmer and it pops back.
I had the dash out last year and checked for obvious ground-fails, cleaned some ground connectors and bought a new headlight switch from ebay.
But it didnt help.
There was a water leakage from the front window to the fusebox a couple a years ago, and so i took the fusebox out, cleaned it, got new relays and fuses. But I guess it still could be a problem there, but Im not sure.
I cant make the lights disapear when I want to. Knocking on the dash, messin' with the headlight switch. It always happen when Im driving.

Anyone who has experienced the same problem?
Any tip would be great! Cause Im stuck!Best regards
Aasmund


 

There has to be a place where tail lights and instrument lights (but not the headlights) meets??  

chase all the wiring from the headlight switch back into the harness as best you can to start with, the red wire is the main power input for the light switch, also if its a later car there may be a grey wire which powers the dimmer wheel but this would only affect the dash lights not the tail lights

Hi John, thanks for answering I followed the wiring from the switch, as you said. Removed old tape and found out that the backlight wire was all rusty inside.
I followed it to the fusebox, going into the rear conncector called A (i think? its a big blue connector) and then continuing to connector B (? the red one). Here it looked pretty nasty with burned marks.
I guess this explaines the tail lights!

But then, what about the dash lights?
Looking at the headlight switch connector; (tried to upload a picture, but didnt work)
Ive noticed that the brown and black/yellow wirings (hanging on that circle-thingy on the connector) is a bit loose. I think the brown is ground for indicator lights? But what is the black/yellow?
Im not losing my headlights when this happens. So I guess its not the powersupply (red wire), or do the headlights get their power from someplace else?

 

brown is earth for the little light in the bulb as you say, the thick black/yellow is the power input for the dip and main beam feed, if theres a thin black/yellow this again is for the little light in the switch.

it may be with all the corrosion you're loosing voltage which means there isnt enough power to run all the lights at once if that makes sense? I would start by fixing up all the damage then see where that gets you!

Yeah, that makes sense.
I'll set up new tail light wires and plugs (if that is the right word) from the fusebox to the switch, and also get a new plug for the power supply wire. Since its also connected in that burned rear connector on the fusebox!

hi ,
i have the same problem .
when i switch the lights , the headlights are working but rear lights NOT . same as the dash lights and stop lights . also the instruments are not working (fuel gauge , coolant temp and Revs).
the fact is that the rear indicators are working the same as indicator light from dashboard and flash light from dashboard are working .
Cheched the wires . when i plug the tail lights connector from back of the fusebox to another pin they light up . that means the wire is okay .
please help .

sounds like your rear clusters need a good buff up, make sure the bulb holders are all spotless. either that or the earth is bad so check that too

thank you ,
i will manage to clean the rear clusters next days .
but how about dash lights ? any ideas ?

are your number plate lights working? check the black wire from the ignition switch to the cluster this is your ignition live feed

nope . they are not working . maybe i just didn't wire them.
i still cannot make my rear lights work .
the problem is that the connector for F is not original and instead of one big connector for all pins there are 2 DIY separated connectors for 4 pins each . and when i connected the wire for brakes to the pin for rear lights it worked but anyway no signal when i press brakes with the wiring done correctly

I think you just need to go back over it all again:
http://www.clubgti.com/showthread.php?219775

the plate lights are fed from the same power feed which poweers the dash light dimmer so this is a clue perhaps. later cars they are both on the same fuse, but early cars the dash lights are not fused. So as a first check see if the fuse for the plate lights is ok