Buick Rendezvous One Dim Headlight - Electrical

[Nick1994]

So on my mom's 2003 Buick Rendezvous AWD it's been having an issue with the headlights. The passenger side headlight is nice and bright but the drivers side is very dim. Also, the high beams are on with the low beams but are super dim and the fog lights are on and dim too. There's supposed to be no way for all of those to be on together, and the left front turn signal doesn't work right, it sort of flashes but also flashes the brights and low beam? Also on the instrument cluster the left arrow indicating the turn signal is stuck on and dim. Also occasionally there's a message on the display that says "Service Vehicle Soon" - NOT service engine soon, that's different. The service vehicle soon I've Googled and usually has to do with lighting issues. Sometimes if I smack the bumper or hood with my hand it fixes itself and the low beam is nice and bright and the other lights go out. I swapped the low beam bulbs and it didn't make a difference. I checked all headlight and fog light connections and they're nice and tight. I'm assuming it's a ground issue but I can't find any ground connections. Is it possessed or has anybody experienced something like this?

Thanks

 

[901Memphis]

Bad relay?

 

[Olas]

Bad earth? Lamp started to go high resistance? Excessive volt drop?

A multimeter is all you'll need to diagnose it

 

[eljefino]

If this car has daytime running lights and I think it does, there are a pile of relays and diodes to make it all tick.

You're backfeeding something through something else, so you have two filaments wired in series, each getting 6 volts, more or less.

The bumper smack says ground. The Service vehicle light shows its cognizant of its situation.

lightsout.org has info on how to kill your DRLs but will also have schematics explaining them.

 

[The_Eric]

Definitely sounds like a ground issue.

Check G101, which is the ground for the left headlight assembly ( and a few other things too):

Ground G-101
Left Side Of Engine Compartment, Right Of The Left Headlamp, On The Front Upper Crossmember

 

[caravanmike]

had a 1992 s-10 with same issue. found bad ground that fed that
headlight only.