Got out of the truck the other day at work and noticed my taillights were out. I walked around the front to see that the front markers were working. that evening when I was about to leave work, I flipped the lights on, and again the tails were out. When I looked about a minute later they had come on. Tried again yesterday, turned switch on, no tails, went in the house to grab my testlight and came out to see the lights working. Is there a relay that controls the tails separatly from the front markers? The sigs and stop light work fine, hopefully ruling out bad ground. I also followed the harness all the way to the firewall, shaking and bending it all the way along, to see if I could find a short. Any suggestion wouold be greatly appreciated.
Thank you,
Dave.

Alot of times the board that the light bulbs plug into gos bad, Ive seen it happen more times than I can count. Its an easy and fairly cheap fix, I think I got the new ones from Napa.

Never thought of that. I'll check them out. Thanks.

your model year truck is notoriuos for the T-Harness in back getting water in it and getting a small short. we have a 2000 crew cab dually with a 6.5L and that turd constantly loses the rear tail lights and side marker lights. go back and wiggle the harness and they'll come on.

If that's the problem pull the harness apart and put some dieletric grease in there and put it back together.