Battery hooked up backwards



Ok, I’ve worked on cars for years and did something as boneheaded as this, yes I hooked up my car battrey backwards.

After setting it right, the car will crank but won’t start. Any ideas what might being going on? Is there a reset switch, or a blown relay that I should be looking for? It seems like the fuel pump may not be running.

The car is a 2000 Daewoo Leganza.




I would check all of the fuses first. If you are very lucky, that will be the only problem. You also may have burned the fusible link in the positive battery cable. (The fusible link is probably OK since the engine cranks)

The main concern here is that the electronics in the car have very little tolerance for reverse polarity. You may have damaged all of the computers, sensors, alternator diodes, etc. Good Luck


I was afraid it might be something like that.


I’m curious what you found out.

I just did similar. Tried to jump start but last cable connected to painted metal. Now my van won’t start.

Please post what your results were.


I had a dealer do that once to my 1965 Sunbeam Imp. The car started and ran that way, but the batter light came on so I returned after a couple of miles. They wanted to just reverse the wires, I wanted a new generator starter etc. They reversed the wires and started it, smoke poured from the generator. I got a new battery, starter, generator and a year warranty on all electrical stuff in the car.

Today’s cars are far more sensitive and have far more things to be damaged. You could be lucky. As noted you will need to check a few fuses and other devices and hope the electronics have not been damaged.

Good luck.


There’s more than one fusible link. There will be one or more feeding the chassis power to the fuse block. Go to your fuse block and check for voltage at the input side of the fuses when the key is in the RUN position.