turn signals only with lights off

i just got a 92 s10 about a month ago. its shaved, lowered, painted and has a tweed interior. my problem is that the turn signals only work when the headlights are off. once i turn the lights on the signal lights come on in the cluster like a light is out. all the bulbs are good though. im guessing that when the dash was removed to do the tweed, someone got some wiring wrong. i personally am an electical idiot so i dont know where to start. like i said though, they work as long as the headlights and or running lights are off. any help is greatly appreciated.

It sounds like there may be a poor lamp socket ground on the front two signal lamps. When the headlamps are off, the turn signals CAN ground through the filaments for the side marker lamps. You may also have other grounding problems, but that would be a good palce to start, since they apparently operate normally with the lights turned off. That would tend to rule out the turn/hazard switch and flasher itself.

so what would i go about doing to fix this problem?