What causes mains fuse to blow ?
A large short!. A short is a hot wire unintentionally touching ground- a metal piece of the frame. It will immediately cause sparking and blow a fuse. Also, an electric motor can have an internal short and blow the fuse for that circuit.
To find what is blowing the fuse, you have to follow every circuit that fuse protects until you find the source of the short. Look for burnt wires, like maybe too close to exhaust. Also a shorted wire can be bundled within a wiring harness, touching other wires and blowing a fuse. Since it is a main fuse, you will probably need a wiring diagram to trace all the circuits which that fuse protects. Try to isolate parts of circuits, like disconnecting the electrical connector at the ignition switch and then see if a new fuse blows. Keep working through each circuit like that until you see results. If some part or component is disconnected and the fuse doesn't blow, then you may be onto it- it could be that part you disconnected, or the wiring associated with the part.
Find a wiring diagram and see what all is part of that fuse. Good luck.
Oct 14, 2017 |
Cars & Trucks