So this is a used a car I bought from a private seller almost a year ago. Recently the factory stereo started failing so I decided to install a new one and tried doing it myself. I got the correct harness for the sound system (it has the infinity setup) and put it all together last night.
There were two antenna wires and I couldn't use the smaller wire so I just wrapped it in electrical tape and let it be. There was a long black grounding wire that came attached the new stereo's harness and I attached that underneath a bolt that I think is just attached to the chassis so I'm hoping that's not where the trouble is from. Anyway I had the negative terminal disconnected while I was doing all this.
I reconnect it and everything is working great. The car starts running when I turn the key and the new radio is playing music. Then the lights start to go dim and everything dies.
I go to the battery and find that the negative terminal had become detached while I had the car running. It was a little loose to begin with so I wasn't surprised. I reattach it and try to start the car again but it won't start. Just makes this clicking noise from the area around the ecu and fuses.
Also the headlights are flashing and if I open a door the door ajar light on the instrument panel starts to flash as well as the dome the car. When I turn the key to the on position some of the instrument panel the way nothing happens. When I turn the key to try and start it there is absolutely nothing. No sound, no cranking, no anything.
At this point I'm wondering if I activated the electronics immobilizer? Or some kind of at this point alarm system? I don't think the battery is dead because when I first reconnect the battery the headlights will come on. They seem strong and after I open the door or start messing with it is when they start flashing. I'm bringing it in to a repair shop tomorrow but there are no Mitsubishi dealers anywhere near me so I'm not able to get it into a dealer.
Also I cleaned the negative battery terminal and post and attached a shim post so it's not loose anymore and that didn't change anything.