Pontiac Problems? Ask a Mechanic for Answers ASAP
Normally when just one of the turn signals fails, the problem is usually in the bulb socket. Check voltage at the Light Blue/White wire with the key on and left turn signal on. If you get voltage on the wire, replace the bulb socket. If you have no voltage there then you may have a bad connection at the underhood fuse panel connectors. There is no separate relay for turn signals, all turn signal voltage is supplied by the BCM (body control module).