My Gerbing single controller is flashing low voltage. I measure 12.9v at the fuse block, connector end of battery harness, both y-harness connectors. When I check the controller though the meter bounces around when low heat setting selected but shows 12.9 on high setting. I had heat as I left the driveway but only for a few minutes with controller on full high. Does the collective mind trust think the controller is shot?