I have a 1989 Montero 2 door 4x4, 4 cylinder 5 speed. There is a fuse block just in front of the battery box under the hood. It has 3 fuses 60, 100 and 30 amp. The 30 amp supplies starting and ignition and maybe more. After starting the engine and it revs above idle the 30 amp fuse blows. I measured the current on the 2 heavy white wires attached to the 30 amp fuse, 12 volts and 16 amps at idle. Above idle, say 1800 rpm I read 46 amps. Anyone out there had this problem ? If so I hope you can help, I'm stumped.

I installed a 100 amp fuse in the 30 amp socket in order to test the system. Those large 2 white wires do get hot.

Thanks,
Robert Thompson
Rnilest@msn.com

 

DO NOT substitute a larger fuse than is specified or you risk melting wires and an electrical fire. The fuse actually protects the wires too.

You need to find out what is on that circuit and what is causing the fuse to blow (also check the connections to make sure they are clean and not corroded).

 

"in order to test the system" I used a 100 amp in order to measure how many amps the circuit was drawing. That's how I found out it's drawing 46 amps. I am not running the vehicle with an oversized fuse.

I have a schematic on the vehicle but it lacks enough detail for a novice like me to find all involved areas. I know the 30 amp circuit feeds ignition and starter and probably more.

I'm looking for someone who has had a similar problem and what was needed to fix.