Hello & Welcome,
Can I assume the mechanic you have been using has checked the basics of the system, such as the main blower fuse?
I have a schematic of the main components and it shows a 30 amp fuse in the rear fuse block for the blower motor.
I am getting ready to go pick the car up soon and I can verify this information for you. I am sure he has checked the fuse, but I have learned to never assume anything, so I will verify that fact.
How can I get back to you?
You can just return here or respond to this message, and I will get an email to notify me of your post.
I was also looking at the schematic and noticed that there should be a "Blower Motor Processor" right next to the blower motor itself. It may be a good idea to at least try to replace that module, if you can get one. I would also suggest seeing if you can get an estimate (for free) from another GM dealership in the area, assuming that there is one open. Also, many Cadillac models have their own built-in diagnostic displays for figuring out what may be wrong, so your mechanic may be able to access that to help figure out what is happening.
Please let me know what you hear from your mechanic.
My mechanic says he has checked the fuses. He is telling me that the control unit needs replaced, so I dont know if that is the same as the blower motor processor you refer to. He tells me that it will have to be fixed by Cadillac and that the cost would probably be $1,000 - $1,500.
The last time I got an estimate for a repair at one of the Cadillac dealers here in Denver, it cost me $170 just to get the estimate. That is when I found my current mechanic and he has been servicing the car for the past two years and has always done very good work and at a reasonable price.
My dilema with this issue is he is telling me that the repair can only be done by a Cadillac dealer, why is that the case?
Let me see if I can get you some more information that you can either use yourself or pass along to you mechanic. Here is the first part that shows the blower motor processor. This is the part that takes the place of the blower motor resistor in "less complex" vehicles.
As you can tell from the schematic, it receives a signal from the Instrument Panel Integration Module (IPM) that tells this module to turn on the blower at a particular speed.
I will see if I can find a way to try and display any error information from the vehicle. But if that does not work (which may be the case), then that may be why your mechanic is referring you to a dealer.
I checked on the vehicle's information system, and I did not find a way to display the errors in the AC/Heater system without the use of a class 2 scan tool, which is what the GM dealers have. That may be why your mechanic referred you to a dealer.
I also have the description of the system below, so that you will know what is involved with the system. It is a pretty complex system.
Air Delivery Description
Here is a diagram of the location of the blower motor processor.
I don't usually recommend this without proper troubleshooting, but if you can get a blower motor processor from another vehicle to try (like from a salvage yard), then I would just try substituting one in to see if that fixes it. I say a salvage yard because that part alone runs about $160 from a dealer, and you usually can not return "electronic" parts if that does not solve the problem. The original part number for that part is 52480042.
I hope this helps and gives you some ideas.
Take Care, Greg A.
I just spoke with my mechanic and he did try to replace the blower motor control processor and that did not fix the problem. He tells me I need to replace the Instrument Panel Integration Module and that can only be done by Cadillac. Does this sound correct, based on your experience? Also, do you know what this repair should cost?
If that is the case, then your mechanic is correct. This is because the Integration module will have to be programmed when it is installed. This can only be done by the dealership's diagnostic computer system.
Sorry about that.
Without connecting the system to a scan tool that can communicate with the AC/Heater control system, it would be hard to tell. But if it was the integration module that is bad, that should take about an hour to replace, and maybe 30 minutes to program. I would add another 30 minutes for diagnosis, so that should be about 2 hours total labor time plus the price of the part, which I do not have the price for.