I have an 03 GMC and was wondering if the Chevy taillights are interchangable. and if so what year(s) will fit? I really like the looks of the Chevy taillights. and think it would be "different".:cool2:

Yes it is interchangeable but you need to change the harnesses to the back junction block as well.

Look at the pics in my signature. If you have the harness with the Chevy lights then it is a 5 min direct swap. If you just have the lights then you can either leave the 4th light out and leave it alone or you can easily add the 4th light to your GMC harness. Go to AutoZone and pick up (2) license plate light replacement socets that use the 194 bulbs along with some 194 bulbs and a couple quick splices. Remove the taillight and locate the "lights on only" wire and use a quick splice to connect the socket to it. The other splices to ground. Trim the socket to allow it to fit the Chevy lights along with the sockets on the lights so the GMC harness with fit. You will have to rotate them around but only minimal fitting is needed. Repeat for other side. Takes about 20 min to do and $10 at the Zone. Good luck!

What color wire is the "Lights on only" wire?

I just liked the looks of the Chev taillights better than the GMC and thought they would be different but after seeing them on 03GMC2500HD's truck, it looks like a must do! Now I just have to find some tail lights...What years will fit?

03-up.

Best bet, try a salvage yard that caters to the newer vehicles.

Tom :pig:

I know some people that know some people, maybe I could work out a deal with the GMC's as a trade in...I can only hope :)

Ebay also!

If you can get them with the harness it would be even easier to swap.

when you say "with the harness" what exactly do you mean, The harness from the light fixture to the truck wiring I would assume. I haven't taken the light fixture out so I would like to know if I'm looking for a short harness or one that would run the length of the box to tie into the main, please advise and thanks for the help.
On edit I looked around and think I figured it out, I need the harness that's about 8-12 inches long that attatches the light fixture to the truck wiring:exactly:

I got mine from ebay the pure red ones didnt have a harness though, was told that the avalanche harness will fit over as well, all that I did was do some minor sanding to the light plug and left out the 4th light in the lower corner very easy to do and took about 20 mins to swap and sand the sockets.

On edit I looked around and think I figured it out, I need the harness that's about 8-12 inches long that attatches the light fixture to the truck wiring:exactly:

You are correct!

I found a pair on EBay....$100 for both WITH HARNESSES AND BULBS!!!!!! BBT's gettin' new tails!!!!!!

:cool2:

Tom :ro)

BTW, for the newbies.....the harnesses run from the lights along the rear underside of the box, then they plug into a wiring junction under the left rear of the box, behind the bumper. Just unplug them, undo the wire clips along the harnesses, and take them out.