I was installing a new Odyssey 34 PC1500 battery in my LR Disco II 2004, and yes, I made the terrible, horrifying, frightening, gut-wrenching mistake of attaching the battery cables wrong. I attached what I thought was positive to positive, and upon throwing on the negative cable, sparks flew, the horn blared, and a small trail of smoke appeared somewhere two feet away before I was able to pop the cable off about three seconds later.

I've now learned that there are multiple configurations of terminals, and I had ordered the reverse of what I needed, and had put the battery in how it fit, not how the terminals matched up with the battery wires. Didn't even check... Gah! Man I feel like I accidentally poisoned the family pet.

Is there any built in protection against idiot moves like this? What damage might I be looking at? I'm freaking out.

Getting the correct battery on Thursday.

 

I did the same thing when I jumped off a Blazer at what. Couple weeks ago. Even looked over to make sure the guy had his side hooked up right first. Doh!

Luckily mine was just a touch. Three seconds is a long time. The smoke isn't a good sign, but it might not be too bad. Could just be from sparking. Did a really horrible electrical burned smell accompany the smoke? If yes, you might've fried something. If the smoke appeared a few feet away in the engine bay then I'd guess a fuse. If it came out of the cab... Get ready to possibly fork out some dough.

You may be fine. I was after my embarrassing incident. Hook a new one up and see if it works after you get a new one in her.

 

Thanks for the feel good! Encouraging to hear. Not a horrible burning smell, just the faintest bit. It was in the engine bay, and it was only a small wisp I noticed after the first second or two. Is there a fuse in the engine bay, besides in the main fuse box?

 

I would first just try and hook up any old 12v battery. See if the right things light up when you turn the ignition. Do you have an old battery?
Don't try and start it. Just watch, listen and smell.
Report back what happens.
Do you have a way of reading fault codes? If you get to the ignition lights stage, see if any have been stored. I would guess yes. Turn off, and research the codes.
I've never done what you did so have no other advice. Burning smell could just be wire insulation melting. But if it's got to that stage I would put money on the computers being toast, I don't know.

I thought the battery terminals were different sizes so it couldn't happen. Or at least you could touch them, but not actually leave them on for any length of time.

 

Great, thanks for the advice. I'll try this tonight. I have an OBD II scanner, so I'll check any codes I can. Yup, battery terminals are the same, so I sure hooked them both up.

 

BTDT on an Alfa Milano Verde I used to own. Had sparks, smoke, etc. Ended up frying the alternator but no other harm done.

 

Hilarious! I did it on an Alfa Romeo 164 and took out the brake lights. Never could figure out what went wrong. Sold it before fixing the issue.

I still have 2 Alfas, a spider and a GTV!

 

My guess is that you toasted the Alternator, and blew a megafuse or two at the main fuse box.

 

If there was no other battery attached to the truck, just the one you put in backwards, it most likely didn't do too much damage. fuses don't care if they are in backwards, but the alternator and computers might not like it. Wouldn't hurt to check the wires where you saw the smoke and see if any of them looked burnt or bumpy.

There is a 'smoke theory' for wiring. All wires are full of smoke. That is what makes them work. If you let the smoke out of the wires, they won't work anymore.

 

I saw a great article about how you can refil the wires if some leaks out.