GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hi there, I am Cam. Can I get your first name please? With your unit, you said the blower works but you cannot control where the air blows? Am I understanding this correctly?
Understood Paul, so my 2 thoughts are first, the blower is not working the vehicle or the mode is incorrect. You tested the blower and that is fantastic, so next, when you had it installed and the vehicle turned on, did you feel the blower motor working under the dash? If not then do you have a test light?
OK, you replaced the heater control head, I am thinking its the blower motor controller beside the blower motor. Does the coloured wire from the controller to the blower motor have full power that changes with blower speed?
the blower controller is also referred to as a resistor pack, but with yours, the automatic system, IT is the blower motor controller. The difference is 7 wires in for manual systems vs 3 for automatic systems. And yes, that controller is know for causing issues that keeps the blower motor running after the key is off. The more we talk, the more I think it is that blower motor controller beside the blower motor that is causing the issue.
If I may be honest, I do not agree with what that expert put. first off, there are 4 possible issues. First, wiring. Second, the climate control head or climate control module (you replaced that already), third, the blower motor itself ( You tested and its good) and fourth the blower motor controller mounted beside the blower motor. ITs actually rare the the head is bad. The motor is common, the blower controller is VERY common and wiring is not common.
Correct, the blower is independent from the blower controller.
First picture shows the blower motor controller.
This shows blower motor (right) and controller just to the left.
No, that is 5.5mm socket, much smaller.
That is exactly the correct part. Those fins are a heat sink.
There is one for the front blower and one for the rear but that is not in question. What you are calling the resistor block is that controller you pictured. And seeing the rust on it, I think its been wet and that does shorten the life.
YEs, if this was my vehicle, or I was working on it, and with all your excellent information, I am 99% sure its that part. I would get an AC Delco from GM, and I do not have a current part number. There have many updates so numbers change. As for the blower and wheel, you might end up replace the motor assembly due to that. They are not really meant to come apart.
The wheel is not meant to come off, so if it goes back on then its ok. The staples are to balance the wheel on it. ITs properly called the blower motor assembly.
No, the part with the metal fins is the blower motor controller.
Haynes manual is wrong.
OK, so its not working. that is the updated part. So lets review a bit./ into that you have the thick orange and thick black wire, correct? Do those get power all the time on the orange and have a good ground signal on the black? If not check the blower fuse in the underhood fuse block.
OK, I Am not sure where you are at now. I would urge you to consider the phone call, I get the feeling it will help a lot on this.