A rather spectacular electrical short…

[jtb74168621]

Recently I experienced an electrical short in my 1990 Astro AWD (117,000 miles). After having it in the transmission shop a few times, each time I got it back, I would look underneath to inspect the work. Each time I would find a wiring harness rubbing the right drive axel. On one of the first visit to the shop, I had them replace the motor mounts as they had deteriorated because of oil leaks. I figure, after replacing the right mount, the battery wire to the starter was redirected which caused the wire to have extra slack and rub the drive axel.

I used a plastic strap to secure the wire away from the axel. BIG MISTAKE! After awhile, the movement of the engine caused the battery wire to wear against the motor mount and caused a short.

I became aware of the problem 1 mile from home when a couple instrument lights came on. One was the ABS light. Very shortly I noticed that familiar smell of electrical wiring.

At the one stoplight before home, I notice some smoke coming from under the hood. The temperature gauge looked ok and I still had power brakes and steering so I knew the serpentine belt was still there. I went the last two blocks to my apartment figuring whatever damage being done didn’t outweigh stopping on a 4-lane highway and calling a tow truck. As I pulled into my parking spot I noticed the brakes acting strange, like the ABS was being deployed.

In the parking lot, I popped the hood. I observed the brake line, under the ABS unit cherry red and smoke coming from that area. Thinking there may be a danger of fire, I immediately removed my coat and $300 leather briefcase from the van before doing anything else. 20-30 seconds later, there was a small fire going on. It was the plastic covering on an ATF line which I was able to blow out. I then removed the battery cable and left it set to cool.

A few days later I assessed the damage and found the battery cable as the problem but wanted to determine what other damaged was done. I had to drop the starter to get at the cable to tape it. A hose on the power steering pump was burnt-through from the over-heated brake line and had drained the PS reservoir. An ABS wire that was also passing over the brake line had melted. Did I mention I had the power steering pump replaced a few years ago? I find it interesting that problems crop-up after having my van worked on by others. But I feel forgiving after realizing I may have caused the battery wire to deteriorate by securing it to the frame instead of the engine, however, I’m unsure of that.

I have been able to remove the hose from the PS pump (which is very difficult) and will replace it as soon as the weather warms and it quits raining. And I have used electrical tape to repair the ABS wire and the battery cable to the starter. My battery and alternator are only a couple months old. The battery checked out ok but needed re-charged. I don’t know if the alternator was damaged or if there are other electrical component damaged. But I’m mainly concerned about that brake line that was cherry red. I’m wondering if that should be replaced. Is there anything else I should be concerned with?

I love my van but it has cost me some big bucks while I’ve owned it.

[RABarrett]

I would be more concerned withthe brake fluid in the line. I suggest replacing the fluid, as the excessive heat will have likely changed the chemistry. You are lucky the electronics survived. Check the line by gently shaking it, to be sure the steel did not become brittle. If not, replace the fluid and repair, not rig, the damaged wiring. There is far too much current going through these wires to take chances. The electronics will not likely survive more abuse. Check everything carefully and be sure of the repairs you make. Ray

[jtb74168621]

It is running again and the only thing that is wrong is the brake light and the ABS light on the instrument panel are on. The brake line seems solid, I replaced the power steering hose and repaired the starter wire. I was able get some electrical tape on the ABS wire that was burnt but a better fix will require removal of the inner fender to allow access. It was a major pain to replace the power steering hose.