Here's what I suggest, but then again I'm no genius.
Check for a blown fuse.
Check the bulbs.
Check the ground for that circuit.
Anyway, I will assume you checked the fuse box first. If you keep blowing the same fuse over and over again, then you need to get serious and check for the problem before you do some serious electrical damage.
To be of any more help, we will need to know the year and model of your truck, etc.
Now my story:
My rear lights were out the other night. Brake light worked fine. Cops stopped me!
I had started the car at dusk and my dash gauge lights went out. I didn't realize the tail lights were out too.
My fuse keeps popping and I traced it to my alternator. It still charges the battery at 14V but it must have a short somewhere inside cause when I disconnect the alternator from the circuit, the fuse does not pop anymore.
