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Cadillac Repair/89 caddy brougham



I recently bought an 89 Brougham and and a.c. and heat doesn't work. When turning either on, the light's come on and all buttons seem to work and let you adjust the temp. But no air comes out of vents, hot or cold. There is a click sound that can be heard when turning on but other than that it does nothing. Any of your thoughts would be greatly appreciated. Thanks.


Unfortunately, Cadillacs are notorious for blower motor issues which can be extremely expensive to repair, if parts can even be found.

The first thing you need to do is check the fuses. Go to your owners manual and find out if there are multiple fuse boxes. Find the blower fuse and check it for not being blown.

Once you have eliminated the fuse as being the problem, get yourself a cheap 12v test light at an auto parts store.

Turn ignition on and set a/c to max. Engine need not be running. Open hood and go to firewall on passenger side. You will see a Brown wire leading to a round piece. Pull the wire off this piece. Ground the test light and insert the test light into the socket you removed. If it lights up, it means you have power going to the blower motor and you need a blower motor that can be obtained on the Internet or a local parts store.

Changing the motor and squirrel cage is easy to do.
If the test light does not light, then you are looking at real money!
Depending on the system in your vehicle will determine the replacement parts. If you follow that blower motor wire to a module that has all sorts of wires going to it and if it is mounted on the top of the a/c plenum,the part you are looking at is known as aresistor module it is non-serviceable and controls the fan speeds.It is dealer only, about $500 and as of a couple years ago that I was aware of, the last one in the world was found.

If this is your situation, the only repair is a toggle under the dash that will control off and high speed as a bypass. You will not have lower speeds.

The other Ser up if you do not have the resistor module is that the fan is controlled by the vehicles computer. Another pricey repair.

The first things though are to check the fuses and the blower motor.

I highly recommend for anyone keeping such a vehicle that they obtain refractory service manual which you should be able to find on eBay or Craig's. The manual will give you diagnostic flow charts for just about anything in the car. It can turn the novice into a seasoned technician on the vehicle.
At the dealer in the day, the service manual was our bible.

The service manual also prevents parts from being changed on a guess. It is a very valuable tool!
Let me know what you find after checking the fuse and the blower.


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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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