hey guys i have a 92 straight 6 cherokee with 230000 miles. i have just replaced the blower motor and resistor to fix my heater problems. now when i turn the heater on the fuse blows instantly. i have tried just propping the blower motor on top the engine and heater works fine at all speeds, when i install the blower motor back through the firewall the fuse blows. i have repeated these same steps 3 times with the same results. any idea why this is happening?

 

Did you have to splice the wires on the motor? Sometimes you have to do that with aftermarket and it maybe wired backwards.
Thats what it sounds like to me since it pops after it is installed.

 

i did have to splice the connector onto the new motor, but it runs fine and at all speeds when propped on the engine. the problem happens once it is reinstalled into the firewall, could the motor flange be grounding to the firewall?

 

switch the wire you might have them crossed motor spining backward fan grounds thru casing

 

ok, old blower motor had 1 black and 1 green wire, new blower motor has 1 black and 1 red wire. I put the blacks together and the red and green together, should i have done it the other way?

 

sweet, switched wires no more blown fuses. thanks for your help.