66 chevelle, When I turn on my lights the gas gauge drops to empty and the turn signal indicaters light up. All the lights and blinkers work properly though. Any ideas on what my problem is guys?????

Sounds like a bad dash bezel ground.
Might try running a short wire to the park brake.

Thanks Dean. I will give that a try. :)

I had a very similar problem on a '64 A-body Pontiac. When I stepped on the brakes, the gas gauge dropped to zero. When I used the turn signals, the radio turned on and off in time with the flasher.

The problem turned out to be the ignition switch. After starting the car, the switch did not completely return to the "run" position. As a result, the multiple contact points on the switch assembly were not lining up correctly and circuits were "crossed" so to speak. If checking grounds doesn't solve your problem, you might want to look into this.

so did you get it fixed? I had the same problem on a 67. it ended up being a taillight socket. it was shorted out and everytime i would send power to the lights, they would in turn send the power on to ground, messing up my gas gauge and lighting up my dash lights