Hi guys,

I am still scratching my head over this, so I'm hoping that someone can lend some insight...

I was leaving work last week in my '89 coupe, around 7:00pm. The car was still just warming up and I wasn't more than a block or two away from the parking lot. Windows down, music on, looking forward to a nice easy drive home when suddenly I hit a bump in the road and everything went black and the car rolled to a stop. There was no power at all!!! Gauges: dead, radio: dead, windows: dead, door locks: dead, lights: dead... everything was DEAD!

I tried the ignition a few times, which did nothing so I quickly jumped out of the car and popped the hood (of course, the underhood lights were dead too) to do some quick diagnosis. Luckily, I was on a rarely used road so I didn't have to contend with a lot of traffic. I replaced the alternator with a high-amp unit less than a week earlier, and I know it was putting out good voltage (13.8v-14.4v steady). I also replaced the positive cable from the alternator to the distribution block behind the battery with a thick 4-gauge wire with an in line 60 amp fuse.

I started fiddling with the positive cable's connections at both the alternator and the distribution block to see if they were loose. Nope, nice and tight. I disconnected and reconnected the batter cables. Still no power. I visually checked the in line fuse and it was fine. I checked the rest of the fuses in the fuse panel - they were all fine too. I thought, "Maybe it's VATS?", but I know that it wouldn't shut off the power - it would only disable the starter. Just as I was about ready to call for a tow truck (would have been the second time this summer!) I pulled on the positive cable from the alternator one last time to get a better look at the in line fuse and - like magic - the power came back on!!! I fiddled with the cable a few more times to see if the power would go out again and everything seemed fine. I quickly dropped the hood, started the car, and drove home without an issue. Heck, I even made a stop on the way home!

I have no idea what I did when I got the car running, but I am scared as HELL to drive it now! I've pulled the battery and plan to get it tested within the next day or two. I removed the new 4-guage wire and in line fuse and will be reconnecting the car's original wire to the positive post on the alternator. I'm also cleaning up all the connections at the distribution block behind the battery too. But I'm not convinced that this is going to solve the issue.

I really doubt that this is a fuel, ignition, or even an ECM problem - I think this is a simple ground/shorting issue. But I'm no electrical guru, so I really need some help here. Should I be looking at anything specific? Has anyone else had this happen to them?

Thanks very much in advance

P.S. Sorry for the long story, but sometimes when I write things out it helps me to remember exactly what happened which can help me formulate a potential solution

 

I would suspect the in-line fuse holder that you added to the circuit first and the wiring & or the clutch saftey switch....you do have a 6spd?

Those are my two choices but I'm not a mechanic!


Tom

 

It gets very dirty there once in awhile. I cleaned down there real good. In your case, it was just a bad connection somewhere. Been there, done that!

 

Typically the alternator wire doesn't even have to be hooked up for the car to have power from the battery so I think you're being misled by your pulling on that wire and assuming it did something.

The only thing it might have done is wiggled the distribution block enough for something to regain contact. I don't know how an 89 is set up electrically but on my 96 the positive from the battery goes to a distribution panel and from there to several other places around the vehicle.

You need someone to post a wiring diagram or get one for the charging/starting system and I think you could find what happened. The fact that the whole dam car was dead should make the search a bit easier.

 

I had that happen to car I owned, I hit a bad bump and the car just shut down. Turned out the battery went bad, do not know exactly what happened to the battery, but I replaced it and the car started right back up.

 

Some options to consider

1) You have cracked plate in your battery, fine when aligned but dead when jolted or moved from a bump.
2) The Vette has a zillion fusible links in the wiring from the distribution block. Every year is different so I can't say what to check.
3) Double check battery ground cable and connection to chassis.

My guess, its the battery.

Larry

 

Well, You've got a bad connection somewhere, it isn't the battery, and it isn't the alternator, as all power was off. I don't have a wiring manual for your car. That would make a difference. I would guess it is in your main dist. block. I know that get's it's power from the + battery lead, might start looking there, then work down to the main distribution block. Here's what happened to me the other day. My O.D. switch wasn't working, and the car was in overdrive all the time. I got to the switch, and checked it with my ohm meter for continuity across the switch. Sure enough the switch was fine. Then I decided to move down to the first connector. I checked continuity from there to switch. In other words I was looking for a bad connection there. I touched one lead of my meter to the one switch terminal, the the other to the end of the wire that was soldered to that terminal. There was continuity, tried the other, there was not. I assumed it was an oxidized connection in the connector, so I disassembled the connector, and cleaned the connections Good. So I tried it again, and had continuity on both wires. I thought, "well that was easy", so I double checked it, and low, and behold no continuity on that same wire. They were only a foot long. I could see both ends of the wire. Then I found it, and I consider myself lucky. The wire conductor had broke off inside the insulation (metal fatigue), do to the shifter being moved to & fro a thousand times. Now that is rare, but can create an intermittent. That could be your problem. However, I am suspecting corrosion at the main red wires at the batt. terminal. I know you cleaned the terminals good, but that oxidation can crawl up into those wires. That or a bad crimp connection. I hate those, and never use that method. I ALWAYS solder the connectors...

Sorry so long, and keep us posted. This type post makes for some curiosity... Good Luck...

EDIT: There can be a broken connection inside the battery. Use extreme caution, as if this is the case, and a spark created inside the battery, WILL make it explode. I've seen it many times. one of which it got into the eye's of the person working on it. Good thing there were two eye wash stations at the shop we were in...