I hate to admit this, but I messed around and crossed my (unlabelled) cables after putting the battery on the charger. I don't think it had a full charge, and I didn't tighten anything up. I just pushed the cable end on the terminal, leaned the seat back, and switched the ignition on. I got distracted with something else, so before I attempted to start (I left the ignition on) I walked away. I turned around and found smoke coming from the closed hood. I switched the ignition off, removed the cables, and lifted the hood. The alternator was smoking and something from the engine bay side of the fuse block was also smoking.

I can see where the alternator is actually charred around the voltage regulator.

The fuse block does not seem melted or distorted in any way. NO FUSES ARE BLOWN!

There is a connector close to the fuse block, inside the engine bay that has been melted. A wire going to it has melted and the insulation has been peeled away from the heat.

Before I noticed that, after checking the fuses and (correctly) putting the cables on, I tried to get something out of the car. It's as if a battery is not even connected.

Also, when the polarity was reversed and I first switched the ignition to the "on" position (before the fire of course), the gauges actually jumped like they normally do, so nothing seemed abnormal until I saw the smoke.

I guess I'm wondering what the likely damage is, and also why no fuses were blown. Should I expect that all/many of my switches are now destroyed?

EDIT:
I also pulled the power fuse (the 30A big metal fuse). It was not hot at all. I checked continuity in the fuse and it is till good. What's interesting, is that there is now no continuity between the two metal "sockets" that this fuse plugs into. I'm assuming that's because of the melted wire, but I'm also worried that the wire melted in the first place because that fuse was bypassed by some one in the past.

 

My guess would be the damage you are seeing is at a firewall pass through connector behind the fuse block. You will have to pull it out and see how much damage is done. I think there is a bolt in the middle and then it should unplug off the firewall plug.

 

Ya it looks like there is a terminal/junction where several positive cables come together before they all feed off elsewhere. That appears to be where the wire has melted. Luckily the fuse block itself seems find, so I hopefully won't have to deal with that. Not so luckily, the wire burnt into my speedo cable which I'm sure will need replacement.

I'm praying that I can just replace these wires and have a working car again. Still not sure why the fuse didn't blow.

 

My thoughts are with you. Gettting up into that fuse block required contortionist skills and a rubber backbone. I had a bad receptacle in my fuse block and at 5'11, I had fits getting under the dashboard.

Whatever you fried, its just a wire, wires can be replaced.

 

Depending on the year, some have a fusable link near the firewall plug on the back side of the fuse box. Sounds like you burnt it up, along with the alternator. Just replace the fusable link and the alternator.

 

This thread may help--pics included. Had to replace my ignition wiring harness.



http://forums.corvetteforum.com/c3-t...plug-help.html

 

I've done this before.... 30 years ago on a Z28. In my case it just fried the alternator, but mine was also hooked up wrong for only a couple of seconds. If I remember correctly I was told you instantly fry a diode in the alternator when you hook them up bassakwards.

 

Hopefully wires inside the harness aren't melted together--we had to remove the insulation from my son-in-laws dash harness because a single wire to the engine cooling fan relay had melted the entire length of the harness on his '86.

Like they said--find all the wires with fusable links and check for voltage on both sides of each link to see if they're blown...it's a long shot but the alternator might still be good.

I did the same thing about a week ago on the '68 rescue car---good thing all the wires to the external regulator and alternator were already fried--LOL....so I rewire everything for a 130 ampinternal regulator/alternator (I left the Voltage regulator on the wheel well for "nostalgia purpose only" LOL

OHHHHH,yeahhhh.....I bought some bright red electrician's tape and wrapped the Positive lead in the battery compartment with it!!!!!

 

I did the same thing a couple weeks ago. I realized something wasn't right when the battery cable end started burning my finger just as everyone in the shop said fire. I just melted the starter wire jacket

 

It's good to know I'm not the only one who has ever done this. I have not had the time to try to fix it yet, but it sounds like it's not the complete electrical system killer that I thought.

Thanks again.