93 Mustang. Changed battery, killed car. What did i do?

[Shorty]

I replaced the battery in my 93 GT today. Yes, it was the correct battery and connected correctly. When it was connected the alarm chirped and all appeared to be well. The problem occurred when I went to start the car.

I disarmed the alarm, got in, and there was no power when I put the key in to start it. At this time some smoke also appeared behind the battery in the vicinity of the ECU. I'll point out some time passed between when the battery was connected and the smoke since I was tightening the terminals. It appears to be directly related to disarming the alarm. There is power getting to (some of) the car as the under hood light comes on and the car will chime with the keys in the ignition with the door open. No gauges, fuel pump, etc when the key is turned though.

So what did I do? I'm guessing the alarm blew when I disarmed it but I'm not sure if that would cause all of this. I looked at the wiring in the area and couldn't find any obvious damage or smell anything burnt. This is literally my first experience with a fox body so I'm not sure what I'm looking at/where/if the alarm would be wired into this area. Anything else that could have blown in that area? I checked the fuse box and everything looked good there. The car ran normal prior to this.

[98MarkVIII]

You sure you didn't accidentally grab a top post battery with reverse polarity ? Double check the ""+,-" stamps on the battery in accordance with your terminals

[talisman]

May have fried the fusible link that is between the battery and the firewall on the drivers side. I had the same thing happen in my old 93 Cobra clone, but I was just driving down the street when it happened.

[Shorty]

May have fried the fusible link that is between the battery and the firewall on the drivers side. I had the same thing happen in my old 93 Cobra clone, but I was just driving down the street when it happened.

Pardon my ignorance, would that be the plastic pieces joining a wire off the negative side? I pulled it apart and the male side of it looked kind of cooked. I thought it smelt a little burnt too but I wasn't sure. If so I think that might be it.

[lowthreeohz]

Yeah, check that first. if that isn't it then chase down the burnt wire(s) and work backwards. hope it's something simple.

[talisman]

Pardon my ignorance, would that be the plastic pieces joining a wire off the negative side? I pulled it apart and the male side of it looked kind of cooked. I thought it smelt a little burnt too but I wasn't sure. If so I think that might be it.

Sounds like we might be talking about the same thing. This happened over 10 years ago, so it's a bit foggy. I thought it was closer to the firewall, but there also might be more than 1 of them.

[sickpony]

Behind batterery in the vicinity if the ecu? Is the battery in the pass floor?

[91CoupeMike]

Did you get the ground wires all in?

I've made the mistake of not connecting all the grounds, make smoke on the 10gauge ground as I tried to start the car.

[Shorty]

Behind batterery in the vicinity if the ecu? Is the battery in the pass floor?

It's in the stock location. I obviously don't know what I'm talking about. There are a bunch of wires behind the battery tray under a plastic cover.

[Dacotua]

It's in the stock location. I obviously don't know what I'm talking about. There are a bunch of wires behind the battery tray under a plastic cover.

Thats the starter relay and many of those wires are fuse links

[VaderTT]

Behind batterery in the vicinity if the ecu? Is the battery in the pass floor?

Shit, you beat me! Except I would have said passenger side kick panel.

[shumpertdavid]

The fusible links come off the positive side, not negative.

[sickpony]

pull the plastic and take some pics.

[Rtanner]

black ground wire on negative terminal, for ecu broken, off, bad connection