Cadillac Repair: Blower Motor Control Module Test, cadillac dealership, imminent failure

Question
Can you tell me how to test a Blower Motor Control Module ?

I am not very handy but I can follow step-by-step instructions very well.

Thanks for your help.

Ray

Answer
Hello Ray,

You did not state the reason for testing it. Did you check all the fuses. You didn't state the make and model of the vehicle. Some Cadillacs come with more than one fuse box. You need to look at the owners manual to determine the amount of fuse box locations as well as where the blower fuse is located.

The only reason for the printed circuit computer board for the heater blower module was to control speeds. A very overpriced piece that was known for common failure for 25 years and yet Cadillac continued to use the module.

Common problems associated with the module--Fan continues to run with ignition off or no blower at all.

At any given time when visiting a Cadillac dealership there would be 2 or 3 Cadillacs with the hood up getting the module changed.

To test the module, if you have the ignition on with the heater or A/c on to max, go under the hood to the module. Check power going in with a meter or test light. If there is power going in and no power at the blower, you need a module that will set you back hundreds of dollars for something that is just due for imminent failure again.

Cadillac made a good a good car, but they had their quirks. Many of their engines were junk off the line and came with a factory knock. The HT 4.1, 4.5 and 4.9 were either good or problems from new. The northstar was known for eating oil. As I stated, another very common problem was the heater blower module.


Rob