Lights flicker and gauge jumps around???

I am having issues with my Duster. When driving at night the lights constantly flicker lightly and the voltage gauge bounces from 14-16volts constantly. I rewired the entire engine bay with all new wiring. I have a ground from the motor to the body, from the body to the battery, and a wire from the mounting bolt on the voltage regulator to the body. Still didn't cure it. I replaced the amp gauge with a voltage gauge and removed the bulkhead connection at the firewall. I have tried a different voltage regulator. I tried switching the field wires around. I have tried every thing I could think of. I am hoping someone will have an idea that I might have missed so I can drive at night without the damn lights looking like a strobe light. Any idea is appreciated even if it sounds dumb. :banghead::banghead::banghead: