I have a 1999 that i put a 2000 fleetside bed and i swapped the tail lights for the nice lookin 2006 tails. I got the tail lights and wiring harnesses off an 06 truck. The passengers side seems to plug in a little better than the drivers side and it works fine. I thought the drivers side could have a bad harness or that the bulbs were bad so i so i swapped out another harness with different bulbs and it still doesn't work. What's wrong or what else could it be? The little plate that you plug in the harnesses up under the bed, could it be bad or does it need to be swapped out with a newer one to work with the newer harnesses? I just don't know

 

So the harness isn’t plugging into the plugs on the back of your frame is what your referring too? Or is it just not working?

 

It's plugging in it just doesn't feel as if it's seated as well as the other. But it's definately not the harness or bulbs cause ive switched them out. Any ideas???

 

I'd check for a bent or backed out terminal end in the connector in the truck's body harness, or a broken wire to that connector...

 

does your old harness still work?

 

It wont snap in if thats what you are referring to... I know it feels like it should snap in or click when you have them properly installed, the dont though, Ive swapped to these on 4 different truck, all of which felt like they werent properly installed. Now if your bulbs arent working thats a different story!

 

I don't know i never had them running! I know that sounds funny but i swapped my sportside for a fleetside and never had the lights running on the truck until now. What could be the problem? I don't see any pieces of the connector broke or messed up.

 

Well it was funny because the passenger side did seem to "snap" but the drivers definately didn't. NOPE, not the bulbs. I've changed them already....

 

Hmm, odd. Id try to change that plate where all the connectors are maybe