One Dim Headlight
I cleaned of the ground and the problem is still there. Th fuses look fine too. Any other ideas of what would cause this. Passenger side headlight is dim, and the turning signals on the passenger side dont work when the headlights are on. The brights are dim too on that side.
Given that both the high and low beams are similarly affected, you should continue to look carefully for whether the shared black ground wire for these lights is damaged anywhere between the bulb receptacle and the ground wire bolt on the engine bay chassis.
1) Have a look at the headlight circuit diagram below. The only explanation for dimming of both the passenger low and high beams is a fault in the common ground wire that leads to G201 ground connection.
2) Note that the Blk ground wire for the passenger front turn signal funnels into the same G201 ground connection.
My pet theory: The wire harness for the G201 ground wires has been damaged somewhere at one location. At this location, the Blk wire for the turn signal is completely broken, whereas the Blk wire for the headlight is only damaged enough to reduce but not prevent current flow, thereby dimming the headlight. In addition, the broken turn signal ground wire is touching the headlight ground wire, allowing the turn signal to use the headlight wire as ground. Turning the headlights ON (high current) may interfere with the turn signal (lower current) from grounding through the same wire.

Last edited by RonJ; Mar 13, 2009 at 02:41 PM.
The reason the turn signals were affected was because the electrical current for the headlight couldn't return to ground. Instead, some of it backed up through the turn signal bulb into the turn signal circuit.
Whenever two seemingly unrelated electrical systems start to strangely interact, it is very often a grounding problem.
Whenever two seemingly unrelated electrical systems start to strangely interact, it is very often a grounding problem.



that's really weird though.......