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Cadillac Repair/car whont start


my girlfreind installed the new car battery with the positive and negative backwords and qwickly fixt it but now the instermant cluster dont turn on and car whont start i checkt all the fuseible links under the hoo an there all good what else coul be wrong its a 1989 cadillac eldorado


You say you checked the fusible links under the hood. Does this mean at the starter? How did you check them? Blown fusible link wire is rubbery when pulled. I would tell you to reexamine the fusible links at the starter.
The problem is that there is no diagnostic flow chart for what can be damaged hooking up a battery backwards.
The instrument panel may just be a gauge fuse. Check the owners manual for fuse box locations, commonly Cadillacs have multiple fuse boxes.

When you ask what is wrong causing the engine to start after the battery was installed incorrectly, you could be dealing with anything. Wiring harnesses can melt in nano seconds. You can't always count on fuses or fusible links. I am also a vehicle fire instructor, so I definitely know what I am talking about.

You are going to have to do things the old-fashioned way and obtain a factory service manual and start tracing wiring harnesses up to the ignition switch under the dash on the top of the steering column. Possibly an ignition switch (not the key lock cylinder) or harness fried.

I don't remember anymore, if you have a black resistor chip on the ignition key, you have the VATS anti theft system. You could have fried that module or even the ECM.

I am at a big disadvantage not being at the vehicle. The factory service manual which you may find on Ebay or Craigs is the best tool you can have right now and in the future. It will prevent you from changing perfectly good parts on a guess.

Damage could be minor or major. I saw a main power wire being accidently put to ground (same thing done here) under the dash. Within a couple seconds the inside of the car filled with smoke, flaming plastic wiring insulation dropping on the carpet. It was disconnected and the dash harness was totally destroyed!
Hopefully we are not dealing with that.
Let me know what happens.

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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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