Tailight Problems

Road Trip said:

What's nice is that both the black & white wires are included in the G401 wiring diagram.

Click to expand...

I sure did seem to recall the ground attached to the bed support was a white wire, but without a working example I couldn't confirm off my truck, since I've just got the black wire there currently. It was badly hacked by PO's, and I've undone about 90% of the hacking. My taillights, signals, brake lights, etc. all work but haven't got the hazard flashers on board yet. (Flasher was melted, replaced it assuming old damage due to previous hacking, still don't work.)

Referencing the factory manual is always a wise choice but I do get OP's desire to confirm from real-world. That almost always makes more sense to my brain than wiring diagrams which tend to make my eyes cross. However, that's the official version, not 25+ years of whatever has happened to these poor trucks once they left the factory.

Richard

Wow absolutely thorough explanations diagrams and help from you all! What a great group. Hope I can return the favor some time!

Just to follow up...

I used alligator clip leads to first connect the black wire to frame, and yes the tail lights all then worked.

I checked the white wire first by connecting it to a multimeter and then to the trailer white connector pin. They

showed closed circuit. I then tested between the white lead and the frame. It was open circuit. So yes that was definitely the trailer ground wire.

I then crimped ring terminals onto the two wires and bolted them to the nearest crossmember after first sanding the spot clean. Then I zip tied the wiring up out of the way where it looked like it had probably fit before. I hit the area with NH Oil Undercoater like the rest of the frame..

Thanks to all, the lights are now sorted out.