Blower Motor Resistor for front AC/Heater

most resistor blocks bolt to the fan housing, be causes its air cooled
and must be near fan actual so it always is cooled. see?
i just looked,its there. dead center blower case.(fsm book)
alldata.com
log in and read the HVAC pages.
if fan fails on high too, its not the resistor, because on high
it bypassed.
ah but not if the thermofuse in the resistor block is blown

I am assuming you checked the fuses for the ac /heater first as you mnever said anything about that.. the resistor block and switch removal can be printed out either by the parts store or dealer service..

What is near the motor? This isnt working on HIGH. So its not a resistor. If that is what you are talking about? High isnt connected to a resistor. Its direct power so what would changing the resistor do if the only possible problems are fuse, relay or switch? If it worked on HIGH and not setting one through three then yes it would be the resistor on the ac blower motor if it is still powering on when tested on the low settings.

See http://www.myisuzuparts.com Always replace the blower motor resistor with a new blower motor.

if the lower fan speeds dont work but the fastest speed does the heater fan resistor block needs replacing. If the highest fan speed doesnt work leave it on there and check for power at heater blower fan, if power is on one wire and the other is an earth the blower motor fan needs replacing. Use a normal globe test light to check this. If no power on any wires to fan go back and check all fuses in car and under bonnet with same test light. If fuses are ok possible open circuit wire to fan.

Replace fan motor and resistor at the same time to fix it. A bad fan motor will burn out a resistor. Clean drain tube at bottom of evaporator case

There was a bulletin reguarding water contaminating the blower motor, which overheats the blower resistor and renders it inoperative. The fix was to replace the blower and the resistor and seal the culprit hood cowl screw at the base of the windshield, which is the second screw from the passenger side. They say water drips off of it down into the fresh air opening.
Here's what I'd do: Assuming your switch and blower motor is good, replace the blower resistor. Remove the blower motor and see if it spins without any excessive drag. If it's okay, reuse it. If it's dragging, it will overheat your new resistor in a short period of time and you'll be back at square one. The blower resistor is mounted to the front of the case with 2 screws to the left of the blower motor. Remove the glove box and you'll see it.
The Hood cowl screw is straight down into the cowl, the second one from the right side, about 10-12 inches from the right fender. Pull it out, put some sealer on it, and reinstall it.

The resistors are in circuit only on the lower fan speed settings.
On the highest speed setting, power is switched directly to the fan motor.
Check fan power supply fuses,
Check power is available to the fan when high speed selected.
If all above OK, apply power directly to the motor to verify fan motor runs- if it doesn't the motor may need replacement/repair.

Replace the motor and resistor at the same time. A motor that has too much resistance will blow the resistor out every time. Been there done that. I've sold a lot of resistors and they had no warranty unless you replaced the motor too.

Get a new blower motor and relay.