Recent post about a short in the radiator fans prompted this...

You have a short the fuse blows, replace it and that blows so you dont make any progress. You cannot use a nail or the wiring burns out so you want something that wont fuse ....Answer a headlamp bulb . Preferably 90w . THIS WILL NOT WORK WITH A 5W BULB OR TEST LAMP

Attach wires as shown with two spade connectors to fit your fuse holder . Push these in instead of the blowing fuse.
Turn on ignition or switch on the device that is causing the fuse to blow. When the short is present the bulb will glow full brightness.
Now if you suspect a short in the wiring ie chafing then wiggle the harness and if the bulb flickers you have disturbed the short. Hone in on the location.
When you remove the short the bulb will glow dimly. In the case of the mega post on the rad fans the bulb would have gone out when the faulty fan was disconnected .

BEWARE THE BULB GETS HOT. SOME USE LONG WIRES 3-4 FT AND HANG THE BULB ON THE BONNET (HOOD) CATCH OUT THE WAY.