For those who have had problems with your tail lights or the harness itself I'm liiking for some info. I've got a 94 Firebird with some possible common issues. The harness that runs from the hatch area plug on the left rear then runs out too the tail lights needs/needed repair. Ive spliced some new connectors on the drivers side since all but the small one were missing. Spiced in the two 2057 bulb sockets and the 1156 bulb for the reverse light. Got power 12volt running to them and are bright. Signals work and brake lights work. The undisturbed passe ger side of harness is giving me some trouble. The bulbs are dinmmer and the vtage is 10-11volts on all positive poles. I know the ground wire was broken but repaired that and no change. I dug into the harness and found a spice that was wrapped with black duct tape. After removing was corroded but can't decide if its a factory splice since all the grounds come together and splice to one wire then splice again to another bundle of grounds and continue to the passenger side of the harness. Ill attatch a poor quality picture but will try to get another this evening.

This splice only pertains to the ground wires as the other powered wires of color are point to point through the harness. Somewhere ime loosing some voltage thats preventing the passenger side from recieving full 12volt power. I am thinking it could be the ground that is spliced causing it to be weaker not being one continuous wire for each ground but it connects the same on the drivers side coming from the left side splice pictured. The bulbs are all new and incandescent(not LED). When applying the brake lights the lights on the passenger side are brighter and the drivers side are dimmer as shown in the picture.

I will try to get voltages with the brake lights on to see if I've got voltage drop on the drivers side in the brake on scenario. Any advice on the wire splice pictured and where to look for this voltage problem would be appreciated.