With all the effort and unnatural angles one must twist the neck and body to get the resistor OUT, it's easier just to replace it. Did mine yesterday (Aug 2010), simple. It cost $22 at Advanced Auto.
It's located under the dash on the passenger side. You'll need a Phillips head to remove a plastic cover, then a 9/32" ignition wrench to remove two hex head bolts. Takes about 20 minutes.
The blower motors also go bad slowly and you'll notice a significant drop on your voltmeter if your Cherokee has one) when you turn the blower switch on. The blower is on the passenger side of the engine compartment. Might be a good time to replace that too--it is accessed by moving the washer fluid reservoir out of the way in the engine compartment, then three 1/4" tiny bolts and a wiring harness clip. You may need a small pry bar to ease the blower motor out as it was likely put in with some sealant.
Be sure to disconnect the negative cable on the battery before replacing either of these things.
if you lost one or two fan speeds you need to change the blower motor resister. it sells for around $60.00 at a dealer only.
You still have a blower resister assembly, wiring, and a blower motor itself, in that system. Any one of those could have a problem. You need to use a test light at the blower motor connector and see if you are getting both power and ground. If you are missing a ground, most likely you have a bad blower resister assembly. If you are mssing power, check fuses and wiring. If you have both power and ground, and the motor isn't working, you need a blower motor. I have also found that sometimes tapping with a screwdriver handle on the motor will make it come on, and if that is the case, then again, you have a bad blower motor.
Check the fuse and relay first. Then check the blower resister, then the blower motor itself. One of these is probably the cause of the failure.
the Blower Motor Resister is located under the Glove Box. its connected to the Motor with two scrows one on each side. dont forget to unplug it. when its out it looks like a card.
double check that it's the motor most times it's the resister for the fan speed In the firewall on the passenger side of the truck is the blower motor speed resister coils, they burn out alot. I could not find one for my Dakota so I got one from a dodge caravan and I changed the wirring, that is the most likely problem
first locate the blower motor, and next to it you will see it. two bolts are holding it, can not miss it 5 or 6 cables connect to it. to have an idea you can get one at outozone first that way you can id it faster. if you have problems with your blower motor speeds one works and the next one don't and the last one does it then is the resistor. to make sure of it you can make a test is got to be continuity in all the terminal...
Well it is apparent that all is not ok. The speed of the blower motor is controlled by the blower motor speed control switch and the blower motor resistor pack. One of those two items is your problem. I would bet the blower motor resistor pack is defective. The only way to know for sure is to replace it.
The most likely problem with the heater blower on your 2003 Sable is the blower resister. The resister can go bad and cause you to only have one speed.
I would check the windshield seal, and the drains for the heat/ac system. If those drains are clogged water will come in through the cowl vents and collect in the system until it overflows onto the carpet.From the Blower motor question below...Recall and Technical Service BulletinThe body style that ran from about '99-'03 had a issue with rain water getting into the blower case and ruining the blower resister assembly and the blower motor. There is a modified cowl cover that is supposed correct this condition. One tell tale sign that you have this problem is pull the blower resister assembly out and examine it. If it has corrosion or rust on the terminals, you have this problem. Replace the resister assembly, blower motor, and cowl cover.
if all speeds do not work id say is a fuse, but if you just dropped one or two speeds. replace the blower motor resister. sells for $60.00 at the dealer.
most common problem is the blower resistor In the firewall on the passenger side of the truck is the blower motor speed resister coils, they burn out alot. I could not find one for my Dakota so I got one from a dodge caravan and I changed the wirring, that is the most likely problem
the switch, or the blower motor resistor, or blower motor usually it the last two at one time