Dash Light Problem

[cl0udedth0ught]

I was wondering if i could get some help. I have been having some problems with my interior dash lights lately. I have a 1979 chevy half-ton 4x4. The right turn signal light stays on dimly when i have my head lights on and my fuel gauge drops to nothing. However, my fuel gauge also goes down when I put my turn signal on whether the headlights are on or not. I replaced the head-light switch and tried a different gauge cluster from a junk-yard which didn't help. However the other gauge cluster had different issues. Only like 2 or 3 of the bulbs on one side would light up and the turn signal lights wouldn't work at all when the turn signals are engaged. Any help for this problem would be greatly appreciated.

[Pontiac1976]

Most likely a bad light or socket for the lights, I would check thing there first, or the wiring there. I'm going two say the rear to check first but could be the front. For the fuel gauge check the red (pinkish wire) to the gas tank might be getting bad connection there.
For the spare gauge cluster did you try to put in new peanut bulbs.

If the spare cluster works after, and does the same you know where to look another place is the rear wire @ the plug in for the rear wire under the bed there is a plug there to hook up the rear tail lights some time they get bad.