Alright, here's one for you electrical wizards on here. I've got a 1990 C1500 Chevy, and I recently noticed a big problem. My turn signals work fine, front and rear, both running lights and turn lights flash. BUT, when I turn my running lights or headlights (which includes running lights) on, I can no longer signal. No blink out of any lights. What could the problem be? Blown fuse somewhere? Has a relay somewhere fried? Or is there a loose connection somewhere in the maze of wires? Any help would be greatly appreciated, I'm not driving at night until that's fixed. Thanks.