I have been having issues with my 2012 g37x sedan. It started out about a year ago my battery and brake light would start flashing the car drives smoothly still and on a random day soon after the lights start flashing I randomly lose all power. The car goes to 0 rpms and I get zero response from gas pedal. In coming days after that the car would start but slowly it wouldn’t be able to hold a charge pointing to alternator. After replacing alternator everything goes back to normal the battery and brake light go away. The cycle then repeats after a couple of weeks to a couple of months. This has happened 3 times so far. Now the issue has slightly changed the alternator seems fine. Now the battery and brake light do not come on. I will just randomly lose all power like before and dash lights up like a christmas tree. I pull over turn the car off and back on and everything is totally fine it drives smoothly. This seems to happen only after driving for about 50-100 miles it has happened twice now. The car doesn’t violently jerk and rpm’s don’t bounce up and down it just slowly falls to near zero. I was wondering if anyone has had similar problems and can give me somewhere to start. I am leaning towards a bad ground. For context the only other issues I have had with this car in 8 years are the sunroof drains being clogged. I recently cleared them and my backseat no longer gets wet. Any suggestions are greatly appreciated.

 

Is it a oem alternator? Aftermarket ones are iffy. I've seen new ones d.o.a out of the box