View Full Version : Heater Blower troubles

November 18th, 2004, 13:05
My 93 cherokee is not ready for winter.

My heater fan/blower only runs when the switch is on the HIGH possition. It is all or nothing.

I am wondering if this is a motor problem or a controler problem.

Which should I replace first. Any ideas would help

November 18th, 2004, 13:23
Classic problem with good write up on the fix

November 18th, 2004, 14:40
great link. used it last year when mine puked. my resistor was fine....I just had some corosion that I cleaned up and it worked like new again.

November 18th, 2004, 15:36
its more than likely a blower resistor problem. the resistor is bypased when in the high position allowing full charging system voltage to the fan for high speed. the resistor reduces the voltage for each of the lower speeds, and when it is burned out you will only have high. a blower motor with high resistance can cause the resistor to fail also.