[evil_goat]

I have a 1991 Jeep cherokee. When I replace the blower fuse, it keeps blowing the fuse before the fan even turns on. The black ground wire to the AC compressor unit it not attached because the cable broke. But that shouldnt affect the heat and blowing right?

 

[4.3L XJ]

Sounds like a direct short. Look for frayed or broken wires. If you don't find them, you will need a multimeter to follow it all out to find the short

 

[evil_goat]

Sounds like a direct short. Look for frayed or broken wires. If you don't find them, you will need a multimeter to follow it all out to find the short

Where should I look for the wires?

 

[Gluckmysock]

I'm thinking it's the blower motor resistor. It's mounted in the blower motor housing and should be under the glove box. Look for melted wires.

 

[4.3L XJ]

So does the fuse blow before or after the fan switch is turned on?

 

[evil_goat]

So does the fuse blow before or after the fan switch is turned on?

I dont know for sure, but the fan doesnt even start to blow when the fan switch is turned on.

 

[4.3L XJ]

Check the resistor first. But you have a direct short for sure

 

[evil_goat]

So does the fuse blow before or after the fan switch is turned on?

The fuse blows after the fan is turned on.

 

[4.3L XJ]

start at the fan and work backwards. Unlug the fan, turn it on and see if the fuse blows. If it does, unplug the ballast resistor and see what happens. Work backwards until you don't blow fuses