Jumper cables hooked up backwards... got issues

370,000 km .Truck had a dead battery after sitting about 3 weeks. When the horn started blaring u realized my error. After charging properly, truck would turn on, and starter turns, but motor wouldn't fire. I went through the fuses and replaced several blown related to fuel systems. Now the truck will start while hooked up to jumpers, but will die in a few minutes after running. Battery voltage shows 12v or less while running. Also, while running I have no radio, no headlights, no climate ctrl, obd scanner does not activate when plugged in, check engine light on. I swapped a healthy battery from my other truck and it did not fix the issues. So yeah I've got issues, I suspect alternator might be busted. I'm just hoping for some help and ideas posting on here. I've had this truck a long time, I hope it's not the violent electrical shock that breaks the camels back...

 

Welcome to the forum.

There are main fuses under the underhood fuse box that supply power to other fuses..
The first thing I would do is to check them, I'd bet you blew at least one of them..

There are a few YouTube on it..

Good luck...

 

THIS ^^^^.

 

Welcome from LA (Lower Alabama)! Good luck!

 

Welcome from North Florida! Good information above, let us know what you find and good luck!

 

I pulled out the main fuse and found one of the links was broken. I have ordered a new one and will update again when it is in... fingers crossed the issues stop here. Thanks for the help!

 

I had a similar issue with my wife's 2005 Sienna. As a temporary fix I was able to swap it out with another fuse, I think it was the horn, but not 100% sure

 

He blew a main fuse, not a small blade fuse.

 

Probably that main fuse will help a lot but will need to figure out if he blew that ground OBD2 wire. He may need to look up info on that part.

 

Defiantly a main fuse, seen it several times. Hooking the battery up backwards is almost a guaranteed time to take the fuse box apart and replace the main fuse scenario.

I suspect with a good main fuse all your interior systems will be properly powered which means the "Key On" signal to enable the voltage regulator in the alternator will start working again and it actually be charging the battery. Hoping this fixes all of your issues.

 

Hope it's the main fuse but it very well could be a fried ECU