Lost power to left headlight. 2008 prostar

did you say if the HI/LOW beam switch still worked?

 

Run the jumper from the R HL and it should work fine, those other issues I'm not sure about, I don't think there you be any issues with running the jumper over. I wish ya luck. Maybe in a few minutes there will be an electrical mechanic come in here and get you a few answers.

Thanks.

 

Yes it does have a LCM and it's probably gone on the blink. Let me see if I can't find a schematic for it.

 

All I can find is there is a Body Control module. Actually a bunch of them feeding a central brain. They are designed like this today for easy diagnostics with a laptop. That's what I would do is find a good shop, preferably a dealer or you'll be spending money wildly on parts. Usually when a body module goes haywire you will experience multiple problems and weird problems. It could also be a bad wire harness shorting and confusing the control module.

Both them headlights have to feed off the headlight relays as there is only one low beam and one high beam relay. It's possible the harness is bad between the head light and relay. That would be my next test point if you are going to try to troubleshoot it. On the low beam relay pin 85 is the wire that energizes the relay coming from the switch. Pin 87 is the main hot output to the headlights. They might use pin 87 and pin 87A to feed each headlight. Pin 30 is the main hot input from the battery. Key on, headlight on... see if you ain't got 12V at each of them pins. Stick your ground probe to chassis ground while checking. Then report back.

 

Ok, for the record, Prostar headlights are controlled and powered by the body controller. There are NO fuses or relays. You cannot jump the right head light to power the left one. The body controller is programmed to put out a certain amp amount per circuit. With the headlights there is one output per light. The body controller measures the amp load on the circuit. If you simply tie in the left headlight to the right headlight circuit you are doubling the amp load which will trigger the body controller to sense an overload condition and kill the circuit. The left headlight power comes from the J2 connector at the body controller, location B, wire A53A 14 gauge yellow. This goes to the top big connector at the fire wall, location 2. Out of the firewall connector it turns to wire #M53A, 14 gauge yellow. From there it goes to the next connector which should be a 5 pin connector near the headlight pod under the hood. M53A should go to location 3 of that connector and come out as C53A. This harness is famous for rubbing on the underside of the hood, bumper and rad. Go along the loom from the headlight pod to the firewall and check for it rubbed through anywhere. Headlights are also a high current draw. Bad connections inside connector will cause the pins to melt and spread causing intermittent or no contact. Check all the connector terminals aswell.

 

You tapped in your CB power at the Mega fuse? Is that what you mean? Radio power supply should always be taken away from electronics. The power supply to the body controller is connected at the Mega fuse. If your radio is back feeding any electrical noise it could be causing your problems. Disconnect the CB and see what happens.