Resistor pack likely will fix fan
By Doug McAllister
Q. You helped me out once before and I enjoy your articles in Sunday's Daily Herald. I have a problem with our 2002 Pontiac Montana. The five-speed fan works on all four low speeds but on five (high) it doesn't work at all. Normally I would expect the slower speeds to not work due to the voltage-dropping resistors opening up.
Why would the high speed not work, assuming that it would normally have 12 volts going directly to the motor? I checked the relays associated with the high speed part of motor, swapping it out with another one without any changes. Any ideas?
A. Thanks for following the column! You are on the right track here. Though it seems counterintuitive, the problem most likely is in the resistor pack.
On this one there is a high-speed relay built into the resistor. I am fairly confident if you replace the resistor pack you will get your high speed back. Take a good look at the connector to make sure there is no damage to it before you plug it back in.
Good luck and I hope this solves the problem for you.
• Douglas Automotive is at 417 W. Main St., Barrington, (847) 381-0454, and 123 Virginia Road, Crystal Lake, (815) 356-0440. For information, visit douglasautomotive.com. Send questions to underthehood@dailyherald.com.