How To Fix Reverse Polarity On A Car Battery. I did a search and nothing came up showing how to reverse the polarity back to what it should be. Beams will put your battery under load.

And the car wouldnt start. Furthermore once a car battery has completely discharged it can be regarded as an empty vessel. I dont understand how someone could hook the battery up the wrong way though.
In theory you have to discharge the battery connect its Charger to it in reverse polarity and turn it on and the battery will charge in reverse.
One battery in our truck has reversed polarityThese two batteries out of our truck - normally wired in series to give 24 volts. Well like spud said reversing polarity wont effect fuses it only effects polarity dependant components like electrolytic caps and diodes basicly under worse case scenario it fried all the parts in the car that have a PCB and anything that involves more circutry that just wires and terminals. Effect of Reverse Polarity on the Battery. The truck hasnt been driv.

