Cadillac Repair/defroster

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Question
QUESTION: I just bought a 92 Eldorado and the defroster is stuck on and I can't figure out how to turn it off it turns off when I turn the car off but when I start the car it comes on and I can't figure out how to get it turned off

ANSWER: Hi,

I am not real sure what you have going on. If on defrost and air blowing out nowhere else. That would indicate a vacuum leak.
Do the other modes on the heater A/C work?

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---------- FOLLOW-UP ----------

QUESTION: No nothing else works at all.

Answer
Hello,

Well, that answers that question. That tells me you do in fact have a vacuum issue. The problem is going to be finding it.
You will need a vacuum pump. They are not real expensive. They are hand held with a hose on it. The first place I would look is under the hood for a black plastic ball the size of a grapefruit. That is the vacuum source from the engine. f it does not hold vacuum, that is your problem.
Otherwise the heater control has to come out and you ill have to apply vacuum to that to see what mode doors are operating.

Good luck!

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Rob Painter

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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?

Experience

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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