Typically it only happens while driving, the warning indicators(service, low fuel, brake) and the dials flash up and down as if the car is just being turned on. While this is happening the car either dies or stutters bad like it's turning off and on.
the battery, alt, and starter has been checked and deemed as good. There is a few loose coil packs that I'm going to tighten down. The engine bay fuse block possibly has an issue. For more than a year the lights( and seemingly power) would randomly dim while driving and odometer randomly goes dark. There has not been dash lights for 3 yrs since I owned it. The door ajar with lights on dinger is constant while lights are on.
please help.

 

@ICT Flips check the car for any codes, in all the modules and report back please. what is the voltage at the battery with the engine running

 

Loose/bad battery cables at the battery or loose/bad ground at the battery, body, chassis can cause that symptom. I had it happen on a 2000 Taurus. It was driving me crazy till on day with the car running, I started touching all the battery cables. The cable that went from battery negative to the fender was getting so hot it burned my hand. Wiggled the cable and the car just died along with some sparks and crackling sound coming from said cable.