What happens if jumper cables are put on backwards

Make sure the voltmeter reads at least No voltage is no current, so your batteries won't discharge. If you reverse both batteries the result may be worse: most likely the device will be damaged, esp. It doesn't matter which end of the fuse holder gets used for going to the battery and which goes to the jack. Fuses don't require current to flow through them in a certain direction so either way is fine.

But typically line is the side that the power comes in on and load is the power going out. Place the new battery in the battery hold-down tray and secure the battery with the hold-down clamp. Spray both terminal ends with anti-corrosion solution. Attach and tighten the positive battery cable Red. Attach and tighten the negative battery cable Black. Any battery or alternator issues that affect power quality will be transmitted to your car.

The good news is that large 12v batteries make excellent buffers against power issues that might otherwise cause damage. However, it is still possible to suffer damage to your car from jumping someone elses. But jumping batteries on cars built after might not be so smart. That's because newer vehicles contain as many as a dozen computers and even more digital devices.

Jump - starting with cables connected to a running vehicle can create a voltage surge large enough to fry expensive computers in either vehicle. What happens if you jump a car backwards? Category: automotive road side assistance. What happens if you connect the negative terminal first? What happens if you hook up jumper cables backwards?

Can you remove jumper cables while car is running? What happens if you touch jumper cables together? Deliberately Causing Sparks. How does it cost to replace an alternator? Why does my horn go off when I jump my car? What happens when you connect the positive and negative ends of a battery?

But, the battery on our Hyundai Tucson died. No biggie, right? Just apply some jumper cables and crank it up, right? That was precisely my thought. Sadly, that is when things started to go poorly. I say that because I got sloppy and did not pay attention. Apparently, this was the critical moment. I must not have been paying attention, and swapped the cables ends when I turned around.

Then, I connected the leads to the battery on my Tucson in the wrong positions. I turned on the minivan. The van started fine. Nothing out of the ordinary happened. So, I had no clue I had done anything wrong. That is because the battery on the Tucson was, as they say on the Princess Bride, only mostly dead. Our school physics lab had a 'cutaway model' of a lead acid battery, which was the result of the teacher's son doing exactly this with a pair of tractors.

That was during, though, not after. I doubt you've damaged the car's wiring loom because the connection was battery to battery directly and the wiring loom was not involved This is not what Rhaomi presented.

He or she connected the black cable to a couple of different grounds, but neither was on the dead battery. This would necessarily involve the car's wiring in the circuit.

I have seen wiring go up in smoke from doing this, when polarity was crossed. Response by poster: Sorry for keeping everyone in suspense -- I'd started writing an update last night but got sidetracked looking at AAA's site. Tl;dr: jumping again did zilch, and there were at least two blown fuses, including the A one for the alternator. Had to carpool this morning, and I'll see if AAA can do a battery test and replacement. Hopefully that and new fuses will get it working again, but no clue if there was more electrical damage beyond that.

Fingers crossed A AAA truck should be able to handle a battery swap and changing out a few blown fuses, they typically have a pretty good kit in there and technicians who are used to solving problems and making things work. I've been impressed by their ingenuity and effectiveness more than once. If you can buddy up to the tow guy a bit when he it's probably gonna be a he, though I'd be thrilled to be wrong shows up, he'll probably go the extra mile for you just to show what he can do.

Treat him like he's a hero and he'll try and rise to the occasion. They can do quite a bit to get your car going again. Response by poster: Hey all, sorry for not updating -- as you might imagine, this ended up being a bit of a hassle. So the fuses were pretty much useless, and even that brief surge was enough to damage the battery, alternator, starter, and a lot of the internal wiring.

The first guy AAA sent couldn't jump it or diagnose it due to the fried starter , so I had them tow it to a local Express Oil Change shop note: always double check where they recommend towing it -- they almost took it to a Hyundai-only place before I caught it.

It wasn't cheap, but they got decent deals on all parts, including a push-button start to avoid having to replace the entire ignition system. Even threw in a free alarm system since the new wiring had to bypass the old one. Grand total was in the high hundreds, though it could have easily been in the thousands or a total loss. It still drives normally a month and change later.