Thanks in advance for the help. My Suburban's AC quit blowing in the front, but would occasionally kick to high and blow. It does have the Automatic Temperature Control. Now, it only lets the cold air flow through the front vents depending on how fast I'm traveling.

When I went to buy a resistor, It had four metal partitions, but the one in my car has a single, thick "blade." Since I didn't buy it, I've read more and am more confused about the cause.

Is there a test to check which unit is the problem. I'm obviously not a mechanic, so other than switching out parts, I'm pretty much lost.

Thanks!

 

The part you are talking about is actually called a "Blower Control Module".

A "Resistor" would be for a vehicle without the auto air system.

To diagnose, put a volt meter on the out terminals of the module when the system is on. You should have some voltage. My bet is that you won't.

I had the exact issue that you describe and the module was the problem. Expensive but it fixed it.

 

The problem is going to be the blower motor control module. This system does not have a resistor, but instead uses a control module to control the speed of the blower. This module is located in the same place as the resistor, next to the blower motor under the passengers side of the dash.

 

I got a letter in the mail from GM, took it to the dealer and they fixed it for free. Last year my rear blower resistor went out, I had to pay for that one.

It may be worth calling your service department and see what they can do.