RE: Headlamp Problem

["Stuart Logan" <stu64@xxxxxxxxx>]

I'm not 100% sure but believe the White/Violet is for the High , or second
element, so jumping it is a BAD idea!
If so, the ground for the Low beam relay is through the High beam elements,
so that when the High beam relay turns on, the ground for the Low relay is
gone, and the relay turns off - jumping it this way causes the relay to buzz
and can burn them out!

With your multitester, With the LIGHTHS OFF, check the RESISTANCE between
the fuse for the headlight in question and ground.  If the connection to the
headlight is good and the headlight Low beam itself is good, then you should
read just a few ohms.

On two occasions recently I've purchased 'brand new' halogen low beams that
didn't work.  The problem is that these lights are fairly uncommon today and
therefore the parts stock is usually very old.

If that checks out, and you have approx 12 volts at the light (engine off),
and a good ground at the light, then it HAS to light up!

If the light works and the trouble indicator is still on, you may need to
replace the 'relay' for the trouble indicator.

Stu


-----Original Message-----
From: owner-bmw@domain.elided [mailto:owner-bmw@domain.elided] On Behalf Of Chris
Gendron
Sent: August 26, 2003 8:26 AM
To: bmw-digest@domain.elided
Subject: Headlamp Problem

I had an unusual occurrence the other day when I stopped to gas-up my 1986
535i. I pulled in, turned off the lights and the engine and filled up. When
I fired her back up to pull away the Low Beam Trouble Indicator light was
on. I got home and sure enough, the left low beam was out. I replaced the
fuse (even though it looked ok), and the problem remained. I replaced the
lamp the next day, but still no light and the trouble indicator stayed on.
The right low beam works, and both sides (all four) work when in high beam.

I broke out my MultiTester and checked the wiring and got these results:
Continuity in all headlamp wires; good ground. Yellow/Gray (mine actually
looks yellow/red) wire =11.99V; White/Violet wire =0.04V. 11.99V on both
sides of fuse when key on and headlamp switch on.

From this I surmised that there is no voltage going from the fusebox to the
lamp along the White/Violet wire, even though there is Continuity in that
wire. I took a piece of wire and jumped from the downstream side of the fuse
directly to the headlamp, and it lit up. But, the Trouble Indicator light
stays on, and a fairly loud buzzing is heard when the jumper wire is
employed. This should be a fairly simple fix, but I am stymied; any
suggestions?



Thanks.



Chris

1986 535i

5sp

193,000 mi on body

28,000 mi on 10-over bored-out rebuild
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