I am having an issue with the passenger tail/brake light. All other lights front, back and interior work as they should when they should. Here is what I have observed:

Headlights off - brake light works correctly when brake pedal is depressed
Headlights/tail lights on - brake light does not work and tail light turns off when brake pedal is pressed

I've checked the grounds and bulbs. What else should I be looking at here?

 

Sounds like a classic case of a bad ground. Just because the ground bolt is tight doesn't mean there isn't an issue with the wire between it and the light. Get a DMM and make sure there is continuity between chassis and the ground pins at the bulb connector. I can almost guarantee you don't. Could be a damaged or bent ground pin in the connector or on the bulb it's self.

 

Like Kolton says.

 

Thank you both for reminding me that sometimes the simplest answer is the correct answer. I had checked continuity from the ground screw to the connector. I had recently repaired the wiring in this area when I had the bed off the truck.

The problem was with the fixture housing itself. Ground wire was all corroded where it connected to the socket. The lens cover gasket was long gone allowing water to enter. I think I will replace both units as they are leaking and rotting. I see several options on amazon and ebay. Anyone have experience with aftermarket lamp assemblies?

 

It seems most aftermarket tails are fairly good. Depo makes some of the best in my opinion.cost a little more but excellent quality.

 

Glad u found the problem quickly. Yes, simple rules.
My taillights neve had the gasker since I bought the truck in 2012. Pls share what u find.

 

I ordered a new set of lights from ebay. They arrived fast and they seem to be fine quality. Everything is working as it should now. I posted some pictures on my build thread:

https://www.yotatech.com/forums/f197...l#post52414447

 

yes, thanks to this thread I found the issue with mine.

It was a bad ground on the brake/running bulb socket.

 

Glad you got it sorted out! Cheers!