Cadillac Repair/headlights


I have a 1994 Cadillac Deville Concours, my headlights kept going out.  Finally found out that it was the fuse so I changed it. Problem is now everytime I put it in drive it is blowing the fuse.  Any suggestions as to why??


The only way you are going to find the problem is to know exactly what circuits the headlight fuse shares. You need a factory service manual to make that determination. Once you find out what is shared, then you can disconnect items from that circuit util the fuse no longer blows. Once you have isolated, the you need to fix what is causing the positive to go to ground.

Let's say for conversation sake that the locks are tied into the headlight circuit. When you go to put the car in drive, the doors would automatically lock causing the fuse to blow. In that case you would be checking the power lock switch that engages when put into drive. This would be located at the bottom of the steering column. To test, you would unplug that switch. You would see if you could put into drive without blowing a fuse. In this case, the problem would be the switch or subsequent wiring.

You should be able to find a factory service manual either on Ebay or Craigs list. Its not difficult to isolate the circuits, but without the manual, you will never find the problem.

Good Luck!

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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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