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Cadillac Repair/1986 Cadillac Eldorado


I was driving my Cadillac and suddenly it stalled. I tried starting it but it just kept whirling over. Finally it started but once I put it in gear it stalled again. I got a boost and it started up. About 5 minutes later I was driving it and it stalled while I was driving again. Now when I try to boost it it will hardly whirl over. None of my lights come on in my vehicle when I turn the key. Do I need a new battery or a alternator or what?


From your description, it sounds like the alternator is not charging. If the voltage goes below 10 volts, the computer shuts down and engine will stall. In fact,  that voltage, very little electrical will work.
Charge the battery. Start the engine and put a multi-meter across the batter terminals. Should be reading 13.2 volts. I bought a meter at Walmart for $10.
Anything less, your alternator is not putting out. When charging with the engine running, you will hear the GM alternator "Scream."

If you do have 13.2 volts or above with engine running, 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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