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Cadillac Repair/89 deville blower motor

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Expert: - 3/30/2010


Question
I have an 89 deville.  My mechanic changed the blower motor.It did not come on. We then changed the the blower motor resistor,(on the firewall). The blower motor came on when it wanted to, and did not shut off, even when the vehicle was shut off.  Then it stopped working.  I purchased a used interior control from a salvage yard.  Still no change.  We have power to the blower motor. We have changed both the blower motor and resistor again.  Still no change.  Thanks

Answer
Hello,

I really do hate these inherent problems Cadillac came with. The problem working with junkyard parts is that you don't know if the part you are replacing is any good.

The problem with not shutting off was very common in the resistor block module.

What bothers me here is you  have power to the motor and will not run. If this be true, there are only 2 possibilities. One being a bad motor, the other being a bad ground for the motor. There are no other options if you have power to the motor.
Are you absolutely sure that the motor is installed correctly where the squirl cage is not binding in the housing?

Now, if you didn't have power- the resistor module could be bad and the one thing you did not change, could be a bad computer too. When these Cadillacs get old, they can be a nightmare to diagnose and repair. That is why I traded mine off for something less complex.

As I said, if there is power to the motor it should either be at 12 volts for high and less with a slower blower speed.

Ler me kow how it turned out.

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Rob Painter

Expertise

Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?

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Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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