2006 W900 lights are haunted. Help!!!

[hhow55]

(10-16-2022 )Grumpyjoewv Wrote:  Yeh that was one of the first things I checked out. It’s pouring the rain here so I can’t trace this out at the moment, but I did find a broken wire connector at the alternator. It’s in the same run with the ground wire ive circled in the pic. Not sure if this is part of my problem but I’m thinking it probably should be reconnected to wherever it goes.

Perhaps the wire in the left picture, is for the ground. I would try that first.

[Grumpyjoewv]

It finally stopped raining. The wire in the 2nd pic that’s connected with the bolt and a second wire is coming out of the 50 amp fuse at the alternator. The wire that’s just hanging is coming from the other side of that 50 amp fuse. Where exactly should it connect?

[Nilao]

Use a heavier copper lug when you fix it. That type that is on it now is probably only rated for 15 or 20 amps.

[Grumpyjoewv]

I have a new copper lug. I’m just not quite sure what it connects to. There’s no signs of it being connected anywhere that I can see

[Nilao]

I would use a multi meter and test for 12v and resistance to ground. It's one or the other. It could be the sense wire as well....it would have battery voltage if it was.

[Grumpyjoewv]

Thanks my friend. I was wrong. The wire with the broken ring and the wire going to the bolt in the pic in my previous are both coming from the 50 amp fuse. I was wrong when I tried tracing it out the first time. The broken wire is definitely the one going to the alternator. I crimped the new brass connector on and heat shrieked it and now I have power to my trailer stop light fuse. It brings another issue though. Now when I turn my key on (not starting engine), most of my gauges and marker lights come on.

[hhow55]

Use a light tester to check the pins on the pigtail to the trailer. If you're getting current with everything off, then disconnect the pigtail from the truck and check the pins on the back of the truck.

Still getting current where the pigtail connects to the truck, go under the hood and disconnect the pigtail from the fuse box and check it there.

I only suggest this route because once my parking lights wouldn't go out with my keyswitch on and it was because the pins on the back of the pigtail receiver on the trailer were corroded and the constant on power from the ABS was jumping over and back feeding up through the electrical system .

[Grumpyjoewv]

Ok I’ll check all that out. The truck is actually unhooked right now so I know it’s on the truck end. I’m sure it’s a bad connection like you said because nobody has hacked any wiring. I have to deliver in 5 hours. I’ll check it out then and post my findings.

[Grumpyjoewv]

Well you’re right hhow55. It’s the trailer abs causing the marker and dash lights to be on with the key. I checked both the tractor side and trailer side of the pigtail and there’s power on two pins that shouldn’t have power until the light switches are flipped. Just to see what happened, I pulled the tractor abs fuse and nothing changed. Pulled the trailer abs fuse and all lights went out. So now I’m about to trace it out between the fuse box and firewall. I’m gettin there slowly and I’m hoping surely!