How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask George H. Your Own Question
George H.
George H., ASE Certified Technician
Category: GM
Satisfied Customers: 18308
Experience:  15+years ASE Master W/L1 Drivability
Type Your GM Question Here...
George H. is online now
A new question is answered every 9 seconds

GM Envoy Denali: Is there a way to test a Blower motor module

This answer was rated:

Is there a way to test a Blower motor module on a 2007 envoy denali with climate control?

Hello I will help you with your question,

There is no direct test without setting up power, ground, the control voltage and th load on the module. Much easier to test in the car with a voltmeter and make sure the module has everything it needs to operate. If it does and it will not run the motor after the motor is tested then the module needs to be replaced.

Please let me know how I can help you

Thank you

Customer: replied 3 years ago.

I did try to test in the car I got around 8v on batt when not working around 13 when working (no control) and I was getting less than a volt on input when working or not it was the same. Probably the module is the problem? I had a friend guessing at the BCM even though the rear blower is working at all times with controls

If you only get 8 volts on the supply then you have a problem with the supply. It is NOT the BCM, please let me know how I can help by posting your readings at each wire color you tested with the blower speed set on high, everything connected and the key on. Use a straight pin to probe along the wire into the connector to read the voltage.


Customer: replied 3 years ago.

To the module on red (batt) i get 8v when not working and 13 when working. On blue (input) i get less than a volt working or not). To the blower motor (purple and black) i get around 10v at all times working or not

I don't understand what you mean when you are saying it in not or is working? Does the blower motor run? Can you control the speed if it does?

Let me know why you are testing the module.


Customer: replied 3 years ago.

It works at times but i have no control as to when it comes on. When it does come on i can control speeds but if I turn it off it will still run even with the car off

What is "IT"? The blower motor?

If the motor is running with the car off replace the module.

Let me know so I can help you

Thank you

Customer: replied 3 years ago.

Yes ``it`` is the blower motor and it does run at times with the car off. So it would be the module then. Thanks for your help.

Yes, the module will not run the motor with no control voltage unless it is shorting inside. Replacing the module should fix the problem. Be sure to look for any melted or burnt connections, if you find them they have to be repaired.

Let me know what I can do to help

Thank you

George H. and other GM Specialists are ready to help you

Related GM Questions