So I had a lapse of common sense and accidentally hooked up the jumper cables backwards while trying to jumpstart my 1996 Maxima. Since I was in a hurry and the battery was all the way down, I disconnected one of the terminals on the maxima so I could jump it directly with the battery in my tahoe.

Soon as I connected the cables I saw smoke coming from the jumper cables which are now completely fried. I immediately disconnected the cables and tried jumping the car with a different set of good cables,but the car will not start.

I have no lights on the dash and nothing electrical in the car works. Ive checked all the fuses including swapping the fusible link (140 amp main fuse) with no success. All the uses are fine. Could it be a fried ECU? Any help would be appreciated. Thanks in advance

 

could it be? yeah it could. is it? I don't know. Double check all fuses and fusible link...ohm out with a meter, don't just look at it either.

 

You disconnected the maxima prior to jumping? And then you connected the tahoe to the max battery via jumper cables?
The max electrical should be fine.

Or did you connect the jumper cables to the maxima battery cables?

 

you might have fried the ECU. make sure you check all of the fuses again, at work once i derped and installed a battery backwards on a Mazda MPV. all that happened was the big main fuse blew, replaced it and all was dandy

 

Check the 140amp battery fuse link. It's bolted down in the center of the fusible link box next to the battery.

 

^^^THIS is a good point. If I understand you, if he unhooked the battery (+) cable then put the (-) jumper directly on the (+) battery terminal, he should not have blown anything fuse wise, right?

 

He said he reversed the wires which to me means the positive of the truck battery was attached to the car's ground, and the ground from the battery attached to the positive terminal of the maxima battery.

 

^^^ Just clarified my post with the addition of a (-) that may clear up what I was trying to say.