Tail Light Wiring

[Chantz]

I've got a 1989 Suburban with a tail light wiring issue. Recently, my left tail light and the licence plate light went out. The bulbs weren't the issue, so I figured it was the wiring. I didn't want to trace it, so I ran a line from the brown wire at the switch to the brown wire next to the tail light. I didn't realize that the wires went to the right and then the left so I killed all of them. However, when I hook up the brown wire again, the right tail light comes back, but the left one doesn't even with the direct line. What gives here? I'm running out of ideas with this one. Oh, and there was a trailer hitch installed original with the truck, so there's a secondary harness coming off of the original ones. My tail lights are torn apart and I currently can't drive my truck like this, so any help or ideas would be appreciated before breaking down and paying a mechanic to trace wires. THANKS!

[MT-2500]

A good wiring diagram and a 12 volt test light is your best test equipment.
The tail light feed off of one wire usually brown back there.
Check where they tied in the trailer hitch wiring.
And do not forget the ground part.
Good 12 volts to it and good ground and it should light up.

[Chantz]

Well unfortunately I've only got a voltmeter and a sub-par wiring diagram. Do you have a place for a better one? I've got a 1990 C/K Pickup manual. Thanks

[MT-2500]

Originally Posted by Chantz

Well unfortunately I've only got a voltmeter and a sub-par wiring diagram. Do you have a place for a better one? I've got a 1990 C/K Pickup manual. Thanks

A volt meter is good as good or better than a test light.
Find the brown wire for tail lights and see where it is losing voltage.
If one side works or has 12 volts start there and work over to other side.
MT

[Chantz]

Thanks for the help. I did trace the problem back to a poorly installed crimp-on connector. The tail light works now, but unfortunately, the licence plate light doesn't. The plastic protector broke, and it's so corroded that you'd never fix it. Should I get a new one or should I just go with something like those neon things that go around the plate? Money says that the wiring is fine, it's just a crappy holder

[MT-2500]

Originally Posted by Chantz

Thanks for the help. I did trace the problem back to a poorly installed crimp-on connector. The tail light works now, but unfortunately, the licence plate light doesn't. The plastic protector broke, and it's so corroded that you'd never fix it. Should I get a new one or should I just go with something like those neon things that go around the plate? Money says that the wiring is fine, it's just a crappy holder

You are welcome and thanks por posting back how it went and glad you got it figured out
Was it one where the trailer light wiring was tied in?
You might want to check your state and local laws on license plate lights.
MT