Blower motor resistor specifications

KEVIN JACKSON JR.

MEMBER
2008 KIA SPORTAGE
2.0L
4 CYL
2WD
MANUAL
179,000 MILES

Does anyone know what the blower motor resistor specifications are? I have been unsuccessful in finding them online and I have confirmed that my fuses/blower fan are all in working condition and I have replaced the air conditioner/blower relay and yet my blower fan still will not function on any speed or setting. I would like to test the resistor which I know still has ohms but don’t know the actual value of the resistance.

1 Reply

STEVE W.

MECHANIC
13,573 POSTS

There are no published specs on them. They are really nothing more than resistors in series with taps at the junctions to give you the different speeds. The high position will be zero ohms. The rest drop the full system voltage going to the motor. So say 12 volts is max, it might be 10 volts, 8 volts then 6 volts for low if you have a four speed fan. An easy way to test the system is to turn it on with high fan. Then look at the resister connector. There will be one that is at full voltage. Connect it to the fans feed line. If the blower comes on full then the rest of the system is working and the resistor is bad. Not uncommon for them to fail.
Sometimes they fail between the resistors, sometimes at the input sometimes at the output. But if you jumper it out you will know.