The glow plug relay isn't engaging the switch to make a circuit and send power to the GB, the GB light on the dash works. Ive tried replacing the relay with a new one, but i still get the same problem. The only way i can get power to the GB is if i jumper the relay, but the car still won't crank, the injection pump was also getting power. Is there anything that would stop the relay from activating the GB/ stopping it from cranking?