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Mixed Up Battery Cables! IDIOT!

2K views 10 replies 4 participants last post by  FunkyKing 
#1 ·
Anybody else ever get totally stupid and switch the cables?

Is my car dead forever or can it be revived? So far I've found the fuel pump, AC and cooling fans want to stay on all the time when the ignition is on, and the DIC smokes after about a minute. Plus there is a relay behind the fuse panel that cycles on and off when the ignition is on.


On the bright side, I didn't pay much for the car and got 3 good years out of it, but I REALLY like it and don't wanna see it go. And I can strip it and use the parts on my NA 9000.
 
#2 ·
Sweet jesus, how did you pull that off? If my battery is backwards, the cables won't even reach!

Maybe someone who has cracked a Trionic ECU can comment on what type of voltage regulation it uses.

I know that the basic 7805's are NOT tolerant of reverse voltages and will smoke. I don't know if the other chips on the board are tolerant of whatever the fried regulator put out. It could be something as simple as replacing a fried regulator in the ECU.

I would avoid powering the car on at this point. If it's running your fuel pump and cooling fans, it could also be running your injectors and god only knows what it's doing to your DI.

My advice, crack your ECU and sniff it.
 
#3 ·
Some more info...The car in question is my beloved 95 9000CS with a FPT ECU and BPC. I had a spare (LPT) ECU which is known to be good. I switched ECUs and there was no difference. It's probably safe to assume that most, if not all of my relays are fried.

If I had just a bit more ambition, I would swap the complete 95 powertrain into my 94 NA (I just happen to have a 94 FPT ECU!), but it seems like a big job.

And the stupidest part of the whole situation is, the car didn't NEED a new battery, I was just putting in a newer battery from a parts car I bought.
 
#5 ·
Surprisingly, I only blew 2 fuses: The radio and the engine diagnostic. And yes, upon closer analysis it seems more like the components downstream of the relays are drawing too much current and causing the relays to cycle. Which is actually much worse than having a bunch o' bad relays.

Or maybe I melted some wires somewhere and that's what's causing all the problems. The engine is mechanically sound and passed smog in January, so maybe I'll do some actual methodical troubleshooting before I part it out.


I remember my exact thoughts as it happened: "Gee, I don't remember making such a big spark when I connect the ground cable to the POSITIVE TERMINAL?????!!!!!!!!!!!!!!!!!!!!!!"

So yeah, I'll either learn to live with 50 less horsepower in my NA 9000, or I'll tackle the challenge of an engine swap.
 
#6 ·
Smoke from the DI would indicate that you've fried it. I would also be very suspect of the alternator and the ECUs none of which like 12V up the wrong way. If your pump and fans run continuously it may indicate that you've got a short somewhere giving constant 12V. You may be lucky if it's just a relay.

Hopefully you didn't try to start it with the battery the wrong way as this will more than likely give problems with the starter motor either burning out or causing mechanical damage by spinning the wrong way
 
#8 ·
LOL!! i did the exact same thing and for the exact same reasons !! Weird!!
I was taking a battery from a 1989 Carlsson and onto a 1996 aero. In my haste, I hadnt twigged the fact that the polarity had been reversed between the models. Sounds like was lucky - only fried my alternator!! ;oops:

What was the final word on the damage here??:nono;
 
#9 ·
The electrician is still checking, but so far it looks like the ECU and the DIC are dead. He'll need to replace those to continue troubleshooting. I'm still bettin' it's gonna be a total loss, based on replacing those parts (at the very least) at full retail price.

Hopefully I'll get a final answer from the insurance company tomorrow.
 
#11 ·
The car is officially a total loss. Looks like I'll get about $2700 for it...which is about what I could have sold it for, on a good day.

Sad part is, I don't have room in my garage to store the parts I wanted to strip from it. So If you're near San Diego, I know where you can get a nice set of Aero seats and door panels.
 
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