The HVAC blower motor will not turn off?

TRISTIN ANDEWAY

MEMBER
2006 CHEVROLET SILVERADO
5.3L
V8
4WD
AUTOMATIC
142,000 MILES

AC/heater blower fan won’t shut off after shutting off truck and keys out of the ignition. Started with having little to no heat and no control of fan speed. Every other setting seems to work. Just recently I replaced the blower motor resistor and connectors, now the fan runs on high all the time and still don’t have fan speed control. Checked all the fuses and tried resetting the HVAC control module with no luck. Any advice is greatly appreciated!

Tuesday, January 10th, 2023 AT 8:28 PM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
50,622 POSTS

It sounds like you have a defective speed control resistor (module) because this is what happens when the resistor goes out. Also, I would check the ground circuit which this guide can help with.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Here are the blower motor wiring diagrams so you can see how the system works, the ground is located at the right pillar A. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem.

Images (Click to make bigger)

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Wednesday, January 11th, 2023 AT 10:59 AM

TRISTIN ANDEWAY

MEMBER
2 POSTS

I took out the module I replaced and switched it out for another one from O'Reilly's but still had the same problem. I had some trouble locating the ground circuit, even though I didn’t take too much time to look for it. Could it be the blower itself or possibly the climate control panel?

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Wednesday, January 18th, 2023 AT 7:40 PM

KEN L