lost my rear lights, 87

[red]

kind of an odd issue that i cant figure out. 1987 chevy 1 ton pickup with a flatbed. I was working on installing a new license plate light (old one was wired into the marker lights so this one is wired the same way). Got everything hooked up and i have no marker or license plate light, marker lights worked before.

currently working: turn signals, brakes, hazards, reverse, front markers, headlights
not working: marker, license plate

Going to each of my rear tail light assemblies are the yellow, green, and brown wires after they run to my trailer plug. The green is my reverse, brown is the ground and the yellow goes to the marker/turn signals. Any ideas what might have happened? bulbs have been replaced and i've swapped fuses around with no change.

 

[btfarm]

Sounds like you are missing a ground wire for the loom (bundle).

 

[red]

checked all the grounds with no change. So i ran a wire directly from the battery to the harness back there, with the - there was no difference, when i connected the + to the + side of the harness it lit everything up (too much juice though of course).

 

[btfarm]

Maybe the hot to that area broke internally somewhere. I think you're going to have to ohm out each wire.

 

[red]

its odd because the brakes and turn signals use that same hot wire and they are working. The truck will be getting a new wiring harness this summer when i do a frame off rebuild, but need it to be street legal until then.

 

[just a number]

the turn/brake wire and the markers are 2 different wires.

 

[handcannon]

kind of an odd issue that i cant figure out. 1987 chevy 1 ton pickup with a flatbed. I was working on installing a new license plate light (old one was wired into the marker lights so this one is wired the same way). Got everything hooked up and i have no marker or license plate light, marker lights worked before.

currently working: turn signals, brakes, hazards, reverse, front markers, headlights
not working: marker, license plate

Going to each of my rear tail light assemblies are the yellow, green, and brown wires after they run to my trailer plug. The green is my reverse, brown is the ground and the yellow goes to the marker/turn signals. Any ideas what might have happened? bulbs have been replaced and i've swapped fuses around with no change.

I'm assuming when you say marker you are including the tail lights as they both should work off the same part of the light switch. What color is the wire for the markers?

According to the wiring diagram for my 94 K2500 the front markers and park lights and the rear markers and tail lights are all tied together on the same circuit, which is a brown wire. This does not mean that your 87 has to be the same, but this is the simple part of the tail/brake/turn signal system. On my 94 the ground wire is black which seems to be common to many others throughout the 90's according to the wiring diagrams that I've looked at. We're looking at two different body styles here so there could be differences, but it would be something to check out.

Don

 

[just a number]

I was reading over the thread and notices your missing one wire. it takes 4 wires total to make it all work. or 3 wires+frame(mounting) ground. reverse, brake/turn, marker and ground.

the old license plate light, did it happen to be a one wire and ground by the mounting bolts?

 

[red]

correct your thinking of the right license plate light. the only other wire back there is a white one but there is no power coming from it at all, has not been connected in years by the looks of it either. I need to find my memory card reader so i can upload the pics, i'll try to find that in the morning.