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Cadillac Repair/Heating on 89 Eldo


Your previous answer was  that mode door under the dash is not functioning properly. You said there might be pinched or problematic vacuum line. Is this line you have  indicated is this under dash or on the firewall or possibly both areas to look at. Does the Climate control panel in the dash pop out  or do we need to try an look from the back of dash from the floor board? Is this vacuum pump something most garages have or would this really  I be looking at dealer for repair?


A hand held vacuum pump might be available at a local parts store for about $20. Explain to them what you are trying to do and they may be able to help you.
The mode doors are under the dash inside the car.
It's been a very long time since I reomoved one of these heater controls. Look for hold down screws for the  dash plate.  Very gently, try to pull the dash plate. There will be 4 screws behind the plate and heater control can be pulled out.
In fact, remove that before buying vac pump pull control out. If there is a cable which I don't think there is on that vintage, the heat mode door is controlled by the cable instead of vacuum.
I do believe on yours it is all vacuum.
Any questions, get back with me.


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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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