Switched Jumper Cables

[Change89]

I read a few things online but I thought I might as well try and get all the help I can before I need to bring it in anywhere so I hope you guys can help. I switched the jumpers cables on my 2005 nissan sentra trying to jump it of course. The other car was fine. No smoke or sparks. I left the cables on there for about 10min and tried to turn it on about 3 or more times before I knew I had the cables on the wrong currents. Nothing electrical works. When the cables are on the right way, I can turn the headlights on so there must be some kind of current right? But the gauges dont move and the engine sounds like its about to start up but doesnt. If there is no cables attached, I've got no power at all. Gauges still don't move, no lights, etc. Checked the fuse box in the engine. Everything seems fine. Checked the fuse box in the driver side. Couple of broken fuses but nothing related to the engine, alternator, starter or ECU. Iv read the ECU could be blown but I want to know what other options I could take before replacing the entire ECU if I have to. I would appreciate any help I could get. Thanks so much.

[elwesso]

Welcome to NICO!

There should be some large amperage fuses under the hood somewhere... I can't believe if you switched the cables backwards that you wouldn't have known. Since you needed a jump, did you ever replace the battery?

http://www.nicoclub.com/FSM/Sentra/2005_Sentra/pg.pdf

Coming right off the battery there appears to be a couple large fuses.

[centralcoaster33]

Sometimes with the fuses in the engine bay, you need a voltmeter to test continuity because a visual inspection isn't enough. I figure you blew a fuse in that box, fusable link or maybe the two small wires from the positive post. Can you get your hands on a loaner battery, one with a charge in it, and put that in the car to see what works and what does not? I don't think you fried your ECU because you'd blow a fuse first and then need enough current to melt a wire and ground out a short somewhere and I don't think you had enough juice for that with a jumper cable.