Hey Guys,

I have a 2012 G37x. A few weeks ago I drove about a hour and a half. I pulled in the driveway and the car wouldn't lock at first from the door. I didn't think much of it as the car locked after a few tries. A few days later the car wouldn't start, so I jumped it and it seemed fine. Then the car wouldn't start again a few days later and my mechanic replaced the battery. One again, after a few days, the car would not start despite the new battery. I am getting no lights on the dash or the ability to use the electronic locks what so ever (I changed the fob batteries just in case).

I'm thinking there is a problem with the alternator, but I do not want to replace it if it could be another problem or an issue with the ECU. My sunroof drains were previously clogged, and I'm wondering if this could have damaged the ECU? Thank you for your help in advance.

 

The BCM (body control module) is mounted on the right side of the passenger footwell and it is below the sunroof drain line.
I would look at that area first.

 

What is the voltage across the battery with the engine running?
Use your multi-meter to test before suspecting the alternator.