i have a 93 GC limited and on the computer display which tells me my doors, tail gate, which lights are out, etc. It says i have rear tail light failure but they both work. i don't know if this is commen for the GC because my 2 friends both have a GC and theirs both have the same problem. Anyone know how to fix it if it is fixable

The problem with the tail-light failure on the display is not restricted to Jeeps. I had exactly the same problem with the display on a Ford Granada Scorpio.

I believe the main problem is down to earthing. The computer senses the condition of the lights by checking the circuit to earth. If you have a faulty earth on the tailights, the the display can indicate failure (even though the lights work fine) This was the problem on my Granny. Remove the lights and check/clean the earthing point.

Also, you mentioned 'both' rear lights are working. On my 93 GC I have the high tail light at the top of the rear window. There are 2 bulbs in that - and if one of those has blown, it will indicate a failure.

BTW - If you dont know, the display will not indicate which bulb has failed, only that one of them has.