2 Electrical problems

[slandier]

I have 2 different electrical problems on my 525i M50 E34 from 1991 (MY92).
1) Right front headlight is not working. I have 12V on the wires, but when I plug the bulb, no light. Left headlight works. Bulb is obviously fine, so are the fuse. I switched the fuse with the left side which is working fine => same story.
I heard that this could be due to a earth problem, but have no clue on how to troubleshoot it

2) Flickering dashboard / instrument panel light
This is a very annoying intermittent failure... The light comes and goes on the dashboard & the instrument panel. I have no clue why. Probably a poor contact as sometimes a bumb in the road causes the flickering / changing of status (on => off or the reverse). But where ??


I'm listening to all input !

Thanks.

Steph

[Kalevera]

#1) - earth problem?! haha. sorry, I've got nothing constructive to add to that one, but "earth problem" struck me as funny.

#2 - remove the dash module and check the connections, perhaps change the bulbs while you have it out. You'll have to pull the steering wheel and air bag if you don't have an adjustable steering column. Check Bentley's for the procedure.

best, whit

[Karl]

Right, if you have power to the headlight, and the bulb will not light, then the problemn is in the earth (ground in US lingo) side of the circuit. Check resistance from the negative (ground) terminal in the headlight bulb connector to ground--should be very close to zero. If you read resistance, check the chassis stud below the hood hinge. Take off the terminals, clean off crud&corrosion, then check for continuity to the headlight connector.

Most likely culprit is corrosion on the terminal, second most likely is broken wire. If it's a broken wire, it's usually easier to run a new wire rather than find and repair the break buried in the wiring harness.

Wish you well with it.