Blower Motor Resister
 

My blower motor only works in one position, high. I think it's the blower motor resister. Do most folks replace the thing or just replace the bad resisters? Any idea about how much one costs?
Thanks and take care.

Dale/cwoflyboy
Retired Coastie
Marianna, FL.

96 2500, 217,000 miles. AT, bone stock (for now)

Replace the resistor assy. Common cause is blower moter pulling excess amps due to oillite bushings tighten up when running.
Not terriblly expensive. Try parts store but believe is dealer item.

My relay was out and my motor was bad but now its all good. The relay is, if your sitting in the driver seat with the panel under the steering wheel off, to the right near your wiper-pulse control. Easy and cheap for a new relay, $5. The motor was considerably more expensive and I didn't have time to wait since it was under 20*F the week it went out...

Mine also ONLY works on high, where is the resistor located?
Thanks

TroyM61,

The resister is next to the blower motor under the right side of panel. It's a retangular box about 3 inch long by 1.5 inch wide. It has 4 terminals on it. You can test it by removing it and do a continuity check between each connector. You should have continuity between each connector (the amount of resistence will be different between each combination). If your is like mine (only works on "high"), you will only have continuity between two of the four connectors.
Take care.

Dale/cwoflyboy
Retired Coastie
Marianna, FL

96 2500, Big cab, long bed, AT, bone stock (for now)

On my 97 there a resister pack that has taps for low and med speeds. The high speed does not use the resister pack. It sounds like either the resistor pack is bad or the fan switch. I'd remove the resister pack and ohm it out with a volt/ohmeter as was said earlier.

Here is how I reached my resister pack. Go to the passenger side and lay on the floor. The resister pack is near the fan blower motor and kinda behind it(you will see it sticking down) and has 2 screws holding it in. The wire bundle from the resister pack can be seen if you follow the wires from the right side kick panel near the door going to your left across the blower motor. My wire bundle had black rubber tubing covering 2 or 3 wires and it connected directly to the resister pack. It can be disconnected near the door panel and the resisters can be ohmed out or you can probe the other side on connector for 12 volts on one of the pins.

A few times last year I have lost all speeds but High and unplugging the resister pack and plugging it back in cured it. I have never found the problem the real problem because the resister pack checked out ok and I had 12 v to the connector on the resister pack....weird. Someday I expect the resister pack to fail. Can't fix it if its not broken.

The heater blower motor resistor is located on the passengers side of the truck on the bottom of the heater/ac box and is right next to the blower motor itself.To remove it all you need is a Phillips screwdriver and take out the two screws that hold it in and unplug it.Re-installation is in reverse and other than you having to bend like Gumby to get at it,its not a big deal.

The photos below are from my recent change of resistors and what mine looked like when it was removed.The shot shows that the resistor had failed and I had lost the bottom two fan motor speeds but still had the top two.The shot of the bag is the part number for the resistor for my year of truck.I am not sure if there is a difference in the years as far as part numbers go.Cost was $63 from Ma Mopar........Andy

Thanks to all of you, couldn't do it with out you.
Thanks
Troy

If the motor runs on High all the time even when the switch is in the off position you have a short to ground in the wire between the resistor and the motor. I had one where the wire goes through a clamp on the bottom of the dash just below the glove box.

I am also having this same problem. I replaced the heater resistor (the metal arm was broken where it was soldered) and it fixed the problem for a while. I am now back to only having high speed work. I am starting to think I need a new blower motor. Any other ideas as to what it could be. Anyone use an aftermarket heater blower and if so is it louder than factory? How much $? Thanks in advance. - Matt

I don't think your blower motor is bad. The blower motor is one speed motor. You proved it works cause it works on high. The blower motor relay supplies 12v to one side of the blower. The other side gets a gnd alone (if on High speed) or thru the resistor pack to ground. So the resister pack with the blower speed switch makes the blower appear as a 3 speed motor.

The resister taps just puts different resisters from the blower switch to ground causing the fan to run slower or faster depending on which part of the resistor pack is selected to ground or, if on high, the resister pack is bypassed and just gnd is switched to the blower.

You could have a wire that is grounding out (as was suggested earlier) the resistor pack causing the high speed but your blower is working. Either the blower switch is wacky or somehow the blower is getting gnd which shorts out the resister pack.

The resistor block has an internal thermal fuse that will go open if it goes over a certain temperature. If you're seeing repeated resistor failure, or short resistor lifespan, you can assume that the blower motor is wearing and drawing more current than it should.

I didn't know that there was a thermal cutoff in the blower but that makes sense. Some motors have a thermal cutoff breaker so they will overheat and the internal breaker pops until it cools down and the cutoff resets. Good point there. So it could be a bad blower.

What I meant was that the thermal fuse is actually part of the resistor block. It's the part that normally fails. However, it may be a worn out blower motor that's causing it.

My A/C blower went off one hot day about a year ago, it seemed as if there was just the slightest amount of air coming out, rolled down the windows and hit the road. As I'm driving down the freeway it comes back on. Everything is fine for awhile and it does it again. This pattern continues maybe another 4 times in the course of year. Couple weeks ago it stops and don't come back on. Do a little research and find this forum and topic talking about blower resistor. Sound reasonable resistor gets old from heating resistance changes Bingo sounds like an excellent possibility of a resolution. Order a new part install it in 2 minutes Bupkis, zero, zip, zilch. OK back to research and I find another suggested possible problem the IGNITION switch. Anyone here know anything about this possibly being a reason the blower motor wouldn't function? What's odds it's the blower motor itself.