One side dim? Ground? Where?

[citizensoldier]

I know this is most likely a ground issue because we all know the electrical gremlins that plague these trucks.BUT? Here is the deal, I have the passanger side headlight,front marker and side marker nice and bright. The drivers side all three are very dim. Where is the ground for that side of the harness? Is it grounded through the high low switch? I can not seem to locate it. Is something else causing this? I don't have a wiring diagram for these trucks yet.

 

[nattieleather]

It's been a long time since I've had a M880 to play with so I can't say from memory where the ground is, but I would say trace the wires. On the head light you have three wires low beam, high beam and ground. Trace it back to find the ground and fix it. Same with the marker lights. That should fix the problem.

 

[goodbrewing]

I will try to remember to look tomorrow but I believe it is on the radiator support. Like nattieleather said follow the wires back from the bulb. You won't have to go far. Also make sure the bulb connection isn't the problem.
Good luck

 

[citizensoldier]

Thanks for that manual Maxim I saved it to my compooper. On the manual wiring diagram it shows a ground next to each headlight. Mine did not have that. The ground from the left side went back into the harness over to the other side and was grounded next to the right side headlight. It was just fastened onto one of the screws holding the windshield washer tank on. I removed that and grounded it to a better spot. I then spliced/added a extra ground on the left side and problem solved. All lights are nice and bright and blinkers working as they should.

 

[319]

Thanks for that manual Maxim I saved it to my compooper. On the manual wiring diagram it shows a ground next to each headlight. Mine did not have that. The ground from the left side went back into the harness over to the other side and was grounded next to the right side headlight. It was just fastened onto one of the screws holding the windshield washer tank on. I removed that and grounded it to a better spot. I then spliced/added a extra ground on the left side and problem solved. All lights are nice and bright and blinkers working as they should.

Angel said.....""

 

[gimpyrobb]

Now to fix the "dim" owner.

 

[Elwenil]

Now that you have the grounds fixed you can gain a lot more power to the headlamps if you run relays on the high and low beam circuits that will take the load off the switch.