Light problems

[67Cuda408]

I am currently having a problem with the lights on my 80 c10 pickup. When i turn the headlights on the tail lights dont work but when i turn the headlights and the turn signals on then the taillights work? Same with the brake lights they only work with the turn signals on? The only possible problem i could come up with would be the turnsignal switch. Any other suggestions?

[dustystrucktoo]

Tell you what, I just got done with re securing my wiring after installing a power for a trailer brake power.  I had pulled a wire and disabled a back marker., then I lost one of my extra blinkers.  and ended up with having my right go on with my left blinker in the front..  I ended up disconnecting the whole back end and reconnected every wire.  and a couple of ground wires.
For me, I have yellow to driver side blinker and brake.  Brown is marker/ tail light.  Grey is Passenger side blinker and brake.  Light green is reverse..  I do also have a few black wires as extra grounds.  to the upper part of the frame.
If you didn't mess with any wires, I would go for the ground wires and make sure they are good.

[Captkaos]

Check your grounds.

[Irish_Alley]

x3 for the grounds

[67Cuda408]

Ive been checking the grounds and more lights are working then before but i still cant get the tailights to work and when the left turn signal is on the right is also. I cant find anymore grounds ive been over the truck like 4 times already any ideas of any i could have missed?

[Irish_Alley]

that problem that you say now about the left turn signal turning on the right thats should be a ground problem. does any of your "tail" lights work by them self if not that might be in the switch.

[67Cuda408]

Its a stepside so arent the turn signal and taillight bulbs grounded through the socket?

[Irish_Alley]

not really familiar w/ a step side but i would imagine that there is a ground wire comming off the socket and going to the taillight housing but you also need a good connection between the bulb and housing

[ccz145a]

.. and the housing to whatever it's bolted to.

[GoatBeard]

I don't know that it would matter in this situation, but make sure your ground strap is hooked up.  See picture:

[VileZambonie]

Direct link

click

[67Cuda408]

I found the problem the right tail lights not grounding through the case. Ive tried taking the bracket off and hitting the connection points with a wire wheel and its still not grounding any suggestions?

[dustystrucktoo]

If worse comes to worse...
I do believe that you can purchase wire by the foot and by rolls.  It might be time to rewire your truck lighting.  If you have a wire with a bare spot, it will mess with function.  Either that or get a new factory wiring.  Firewall to lights, you don't need to change the inside wiring.

Good luck.  I hope you get it straightened out.
Dark Green is your passenger side brake and blinker.  I have gray.

[VileZambonie]

I found the problem the right tail lights not grounding through the case. Ive tried taking the bracket off and hitting the connection points with a wire wheel and its still not grounding any suggestions?

Solder in a new common ground and run a ground wire to the frame. Tuck it in the harness or replace the lamp assembly.