XSeries-forum

fuse 104 on the relay board in the glove compartment is blown, is this a relay fault

Could be the control box yes. Glow plugs going short are unlikely to blow that fuse unless they all fail ‘short’ at once and most plugs fail ‘open circuit’. All mine did Worth checking the state of each plug. I think they should be about 1-2 Ohms if working correctly. High resistance or open circuit means a failure (as does a dead short).