2000 Pontiac Sunfire...Keeps blowing a fuse on blower motor. Computer diagnostic doesn't show any short in wiring or in motor or switch. What could possibly be wrong?

suspect motor - take it out and have it tested

Unplug the motor and then put a fuse in the blower motor slot in the fuse box.
With the blower motor still unplugged, start the engine (run for about 30 seconds). Turn on the heater with blower on high (the blower will not come on since its' unplugged, but this will test all other components in the system except the blower motor.)
Turn off engine and check fuse.
If it's good, plug the blower motor back up and then turn the ignition switch on (heater still on high).
Now chek fuse.
If it's blown, suspect that the motor has a short in its' windings. (repalce blower motor)

there are 2 fuses for hvac, witch one is blowing, engin compartment fuse box or dash fuse box?

ok, that fuse protects the control side of the fan motor, the only connection to the blower motor is the relay. the fuse for the motor circuit is under the hood.
so it will not have any thing to do with the motor or resistor.
that circuit goes from fuse to a splice and to the heater/ac control head in dash panel, it comes back out of control head to the coil side of relay.
the splice wire goes to the rear defroster, so that circuit will also have to be checked.
look around at the grid on the rear window, on either side of grid you'll see the wire that connects to the grid on the sides, see if one came loose and is touching any metal, if so that's where is shorting out.
i can send you a wiring diagram and some pics of wire locations if you like. i'll need an email ad. to send them to.
it's a fairly simpel circuit to figger out and find cause of short circuit.
let me know. mws919

at work now, i'll send info tonight. mws919

A short in the control side or the "working" side of the circuit could cause the fuse to blow. By eliminating each componet (or set of componets) you can locate the problem.

check email and let me know, mws919

Did any of our advice help?

LET ME KNOW HOW HE MAKES OUT. MWS919