You are here:

Cadillac Repair/78 cadillac coupe deville

Advertisement


Question
I'm trying to installed a fuse box my old one burnt out

Answer
Hello,

The first thing I would do is try to obtain a factory service manual for the vehicle, possibly through Ebay. That will cover you for any problems you may run into.

This is not an easy task, because first, you need to know what caused the fuse box to burn out. When you determine that, you will need to go to a salvage yard and find a 77-79 coupe (sedan won't work because you will have wiring for 2 extra doors). You will need the fuse box, harnesses at the fire wall. It's been far too long since I looked at one of these and you may have harness disconnect points. I simply do not remember anymore. If not, you will need to remove whatever harnesses are attached to the fuse box. You will need to disconnect battery in your car of course, and remove and then replace the associated wiring harnesses.

The fuse box is the heart of the electrical system. You should find a bolt or two holding the box to the firewall between the engine and the passenger compartment. The box should separate in two pieces, one towards engine, the other in the passenger compartment. You will probably have to remove dash in order to replace that side of the harness. The tail light harness, should have a disconnect. And if the wiring is burned up on the engine side, you will have to replace that harness as well.
You are looking at a lot of work here and the other problem in the 77-79 GMs was the plastics. You will notice for some reason, being old they have an odor. The plastic is also very brittle from age. Not sure why it was just these years, but even the plastic steering wheels and horn trim commonly broke, so be extremely careful.

I have never seen a complete fuse box burn up, and that alone would indicate to me you had a major short in the harness.

As I said though, before you start this venture, get a factory service manual.

Good luck!

http://www.autotheftexpert.com

Cadillac Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


Rob Painter

Expertise

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.

©2016 About.com. All rights reserved.