Just the other day I had a friend install a battery while I was at work. He didn’t realize but the part store actually gave him the wrong one and he ended up connecting the terminals backwards after install. He said it happened very briefly but it still caused quite a bit of damage throughout the car. Immediately multiple fuses blew, alternator went out, and my AMP blew. On top of this I noticed the OBD port wasn’t working so I pulled the fuse (it was ofc blown) and put in another. As soon as the contacts touched the fuse blew again.
All the research and asking mechanical friends tell me it’s either the ECU or a bad ground somewhere along the wiring. So I pulled the ECU and put the fuse back and it didn’t pop.
After putting the ECU back and reconnecting the rest of the surrounding wires I realized the fuse didn’t blow and the OBD is now working.
The codes I pulled were P1065 (ECM power supply unit) and crank/camshaft sensor codes.
Currently the car still runs but the tachometer, speedometer don’t work, ABS and BRAKE light are on, and the headlights and radiator fans turn on as soon as the key is inserted.
I’m lost lol. I’m thinking it’s a bad ground in the ECU but I’ve got no clue.
If you have any ideas or suggestions I’m all ears.