T&JsTORO

Just wondering how much damage I did to my 1966 Toronado after installing the battery backwards. I averted a fire but definitely fried the wiring in the engine bay. Is it possible that I damaged the wiring throughout the car?

oldcutlass

What wiring is damaged under the hood?

Lady72nRob71

Most likely not all of it, but some. You will need to find out which ones abd what the damage extent is.

Rickman48

I'd be getting prices from the aftermarket wireing companies for ALL the underhood wireing to the fusebox, since you'll spend all winter figuering which is good, and which is bad, and what melted together, with the burnt stuff!
Install that, and go from there.
Be happy it didn't burn to the ground!

Jaybird

Damn! Sorry to hear about your wiring trouble!

Lady72nRob71

If looking at new wiring harnesses, think American Autowire. Costly, but accurately made and easy to install.

oldzy

Rock Auto has some good prices on AAW harnesses.

T&JsTORO

Thanks for the replies.

oldcutlass: Obvious damage is along the main wiring harness in the engine compartment. There was a fair amount of smoke eminating along the cowl by the time I realized what I had done.

Rickman48: Yes I'm very grateful that it didn't turn into a car-b-que.

Lady72nRob71: Thanks for the referral on the harness.

T&JsTORO

Just wondering how much damage I did to my 1966 Toronado after installing the battery backwards. I averted a fire but definitely fried the main wiring harness in the engine compartment. Is it possible that I damaged the wiring throughout the entire car?

Fakser

Oh man wires are no good when the magic smoke leaks out you may need to just get them refilled. I told that to my students last week when they grounded a battery cable.

rustyroger

Apart from wiring damage I think the alternator has probably been fried, I don't think any other components will be damaged.

As previously stated you will need a new wiring harness, the insulation will be brittle on any wires that have got too hot, make a thorough job of the wiring so you don't have unexpected horrors later.

Roger.

scumdog

On older cars that trick normally just fries the alternator and sound system but maybe your car is 'newer' than I've done that to.

On a '49 Ford truck it just made the guages read backwards - I was MAKING gas as I drove along!

MDchanic

Yeah... I gotta say I'm a bit confused by this.

Though I've never done the "experiment" of connecting the battery backwards, in any pre-computer car, about the only things that are polarity-sensitive are the alternator and regulator, and the radio (and the HEI if you've got that), and the radio and the HEI would probably be fine with reversed polarity - they'd probably just not work untile you switched it back.

All I can think of that could have caused an overcurrent condition would be flow through the alternator diode set. If that's your problem, then all red wires (except the starter wire) from the battery to the alternator would be burned, but all other wires should be okay (unless they were overheated by the adjacent hot red wire). You could probably replace the diode set in the alternator for only a few bucks, without replacing the whole alternator, IF it was bad.

- Eric

T&JsTORO

Thanks again for the replies. I did some checking and found a better price on a new AAW harness at Rock Auto. (More expensive on the AAW website...go figure) It's described as a "dash harness" and includes the engine wiring. I also need to send them my fuse box so they can build it correctly. I'm still not sure if I damaged any wiring in the interior like power window/seat wires.

Lady72nRob71

Most likely not. The PW, PSt, and PL are not polarity sensitive. In fact the switches intentionally reverse the motors!
Also, any stock accessory that was not on or running at the time of battery connection is most likely okay.
If the key was off when this happened, there is even less of a chance.
Now any aftermarket digital radio, amp, or alarm might have easily been fried if it was hooked to constant power (and most are).

Diodes in the alt and maybe the regulator (if electronic) are the parts most likely to be damaged.
With the battery disconnected and key off, put an ohmmeter across the two battery cables. If low resistance, I bet the diodes in the alt are shorted.
If so, you could unhook the alternator and try again. If the short appears gone, apply a low current voltage source to the battery cables, like a 6A battery charger to check operation of other stuff (and to see what the current draw is (if any)).

If you have no aftermarket electronics, i bet your damage will be isolated to the engine bay. The big red wires there would be the possible smokers. Do some more checking before digging in too deep.

brown7373

Years ago, my son had my 70 Bonneville convertible (kind of a beater at the time) out after I had him clean the battery connections. He left one loose, and it was hard to start and the loose connection smoked and siizzled. It also had a mis match of battery cables, including a black positive and a red negative. He called me to say he had a problem. One of his friends say the sizzling connection and the red cable to negative, so he convinced my son to reverse the cables, like you did by mistake. When I went to help him, one of his brilliant 16 year old friends said "the problem is your old man reversed the battery cables. Any moron knows red goes to positive and black goes to negative." For which I replied to my son, that his brilliant mechanic friend just cost him $4 or $500 because he couldn't see the red cable was clearly connected to ground and the black clearly went to the starter, and that the color, although not correct, had nothing to do with the polarity.

Anyway, it melted some wires in 2, fried the alternator, and if memory is correct, damaged the starter (this was in the mid 80's). I reconnected the melted wires with clamps, reconnected the battery correctly, and we were able to get the car started and get it home for repairs.

oldcutlass

The wiring harness is not that hard to replace as it pugs into the firewall below the master cylinder. I would however, prior to ordering one, pull the old one loose and strip the wrapping off it. You may find only one wire fried, the wire that runs from alternator to the battery. Inpect all the wires and see which ones have the insulation melted. Also as mentioed above, you might consider taking your alternator and voltage regulator (if seperate) to the autoparts store or an auto electric guy, and have them tested. That may be the exrent of your wiring issues.

MDchanic

⬆⬆ Couldn't have said it better myself ⬆⬆

- Eric

T&JsTORO

You guys are AWESOME. Thanks for all the help. I was kicking myself big time yesterday.