2001 Suburban Climate Control system problem

[311Hemi]

I have a 2001 Suburban with climate control. I recently had to replace the front blower motor control module/resistor due to hooking up a battery the wrong way when trying to jump start it at 5:30 in the morning. The control module that was in there got fried. The blower fan works fine, I tested it after this all happened.

After installing the new control module the fan speed dial in the ddash still does not work and I am trying to troubleshoot if it's the new module I put in that is bad, or the fan switch/dial in the dash.

The control module has 3 wires that plug into it (black, grey, orange). Orange supplies power, which I have. I tested the grey and when the blower dial is turned off I get 0 ohms....or no reading (don't remember which). When I turn the switch on low I get around 4.5 ohm, and when I turn the switch up to high I get around .7 ohms. It will increase/decrease continuously while I turn the fan blower dial so it looks like that is working.....but I don't know if I should be testing it any other way.

I tested the black wire and I got around 170-240 ohms when I grounded it to the frame (seemed to range depending on how well I was holding my fluke voltage meter in the connector).....I'm not sure if that is even the correct way to test it.

I can get the fan to start blowing by moving the 3 wire plug around or starting to pull the plug out of the socket on the module, but it's not because of a loose wire. Once I get it to start working it stays at that speed and does not respond to changing the speed on the fan speed dial. I can actually shut the car off, and the fan will keep running. I can then unplug the module and plug it back in and the fan will keep running.....I'm not sure if it has some built up voltage in the module that allows it to run for some time even after the car is shut off or what.

Any of this make sense to anyone? Can anyone tell me how to test the fan switch for the climate control system on this vehicle? It's not a 1-4 dial setting, it's a continuous range of speeds on this dial.

[Jeremy airjer W]

You should way less ohms on the black wire. Closer to 0. Have you tried a jumper wire from the black wire to a good ground?

The other question I have is how much power do you have on the orange wire when its plugged in?

[Macgyver55]

I can get the fan to start blowing by moving the 3 wire plug around or starting to pull the plug out of the socket on the module, but it's not because of a loose wire.

Did you check the connector and module carefully for an overheated or burned terminal?

[311Hemi]

I checked the ground, it was actually pretty low.....somewhere around 1-2.5 ohms. Voltage from was around 12.3 on the orange wire that feeds the module.

I looked at the connector and can't see how there are any issues with it. I cannot figure out how to actually pull the wires and metal part out of the plug. I jiggled the wires around individually and could not get the module to do anything while the plug was plugged in, but once I move the whole plug like I am pulling it off it supplies voltage to the blower, but that voltage remains constant and will not change even if turn off the truck.

The module is new, the old one it is replacing was fried and had a burn mark on the circuit board.

[Macgyver55]

Is it possible they gave you they wrong resistor? They list two different part numbers depending on which system you have.

[311Hemi]

Nope, I matched the part # on them. 16250785 is the part.(ACDelco 15-8794 Control Module Kit)

I bought it through Amazon, so I requested a replacement which should be here Monday. I guess I will know then if it's the part or not.

Not really sure what else could be going on here if it's not.

[Jeremy airjer W]

With everything plugged in check to see what you have for power on the grey wire as you rotate through the fan speeds. It should range from .4 volts to 4 volts.

[311Hemi]

With everything plugged in check to see what you have for power on the grey wire as you rotate through the fan speeds. It should range from .4 volts to 4 volts.

I got .3-.4v at full speed, and 4v and lowest speed. 4.6v when the fan switch was in the off position or the car was turned off.

While testing this the voltage to the fan motor remains constant.

[311Hemi]

It was a defective new part. The replacement arrived today and worked perfectly. Thanks for the help!