I work on a mans 620lp from time to time and someone has wired a 2 blade automotive style fuse in the dash wiring it is wired in with the left side of the amp meter and the ignition switch terminal on the center of the switch just above the coil of wire on the back if I had to guess I would say it was a resistor the problem is whe you switch the light on it shoots the fuse and the tractor dies and won"t restart till you replace the fuse I think it kills the current to the lp solonoid when it blows you don"t hear the click of the solonoid when you turn the switch on am I looking for a short in the lights or do I need to start with a new harness and start from scratch please help me