Blowing fuse when key is in on position

[George the fender]

Hi all. Driving home the other day. George stops dead. No warning or spluttering. Just off and coasting. Discovered the fuse, engine with lightning bolt, 10amp I think, has blown. Replaced fuse but as soon as ignition turned to on position the fuse blows out. Car cranks over fine. New battery. Was going to put a 200amp fuse in to teach him a lesson but decided to give him a chance first. Any ideas? Thanks in advance.

[Tombie]

Yeah.. find the short!

[bee utey]

Wire a 100W or bigger lamp or globe across the fuse terminals, turn on the ignition and start wriggling things. When the light goes out you're in the right area!

[George the fender]

Thanks bee utey. I’ll give it a go.

[BigBlackDog]

That's a lot of amps. It must be somewhere between the fuse, the rally that switches that circuit and whatever the load is for that circuit, I think. Disconnect battery, get a multimeter on resistance, one end to solid earth other end on a long lead and a probe, start poking in the fuse holder and wiggling stuff to see if you can get the meter to go from no resistance (fuse blows) to all the resistance (fuse won't blow)
good luck try not to fry your battery!

[DeanoH]

Wire a 100W or bigger lamp or globe across the fuse terminals, turn on the ignition and start wriggling things. When the light goes out you're in the right area!

X2

What bee utey says though perhaps you mightn't need a lamp this big . For something simple have a look see if the fuel stop solenoid wire has fallen off and is framing to the vehicle ?

Deano