History: I gave a coworker a jump about 4 months back, ever since, my turbo timer stopped working. My drivers side door lock has also made this buzzing sound anytime the unlock button has been pressed, the longer you hold the button, the longer the buzz.

Installed fmic this weekend
Turned car on, started, idled great. turbo timer is working now
Turn on headlights back up, decide to take a pic with the bumper off. Turn off the headlights, headlights do not turn off. I was like, wtf? So i pull the relay for the headlights, that somehow turns on the horns constantly.
I disconnect the battery, horns turn off, unplug the horns.
Take the car for a ride. No dome lights or radio, no power windows or door locks
The only thing working was the sunroof
Volt meter on the turbo timer is showng 10.9 and steadily dropping.
Volts get down to about 9.6 and the radio comes on, windows work, door locks work, I can turn the headlights on and off from inside the car, everything is working perfect.

Car dies, give it a jump at home, back to square one.

This morning i was messing with the fuses and relays. All fuses under the hood looked good. When i pull the relay for the horn, my headlights turn on and i have to pull the headlight relay to turn them off.

The only thing i unplugged was the MAF and a ground wire i have running from the neg post of the battery to the neg wire of the #1 o2 sensor. The o2 sensor was still showing correct voltage while driving. Other than that, nothing electrical was touched

I have no clue as to where to start. The LAST thing i was expecting to have issues with after a fmic install was electrical.
I need some help, Please.