Hey all - I got this 1991 Chevy Silverado C 1500 V6 4.3 L for free as rats had an amusement park near it. It runs great 180 k and fixed all electrical issues But Can Not Figure Out Why the Running lights Don't work --rear or front --All Else is good.. R&R'd relay and bulbs work --no voltage to rear lights at harness -Fuse ok. ???? Ideas as I am a savoy person on electrical

 

I know it is basic, but check grounds, and try to start at the beginning, somewhere, assuming the truck starts, their is power, you just have to find where it stops, then you have your victim. Sort of a prosses of elimination game. I hope that helps.

 

Do both of your turn signals work normally?

I have a 91 C1500 and my signal lever is pretty worn. If I don't lift it to the correct/perfect position, one side of the lights (excluding headlights) shuts off and doesn't work.
So basically I assume there's a possibility that a bad switch can cause both to not work also.

Try the turn signals, make sure the lever rests in a neutral position.
I haven't checked myself but I would assume there is some connection point under the dash to test the switch. If you can find the connection terminals then a continuity test might tell you if that's the issue.
Might not be the issue but is a possibility.