A couple months ago like 4 months or so my battery wasn’t holding charge any more so I bought a new one and the car kept dying so I figured it was the alternator and parked the car up until a week ago when I changed the alternator. As soon as I changed it I went to go start the car car started right up no problem was running great. Left it on till it got to operating temps so then I turned it off and turned it back on. 5 seconds later the car dyes out and I go to start it again and the alternator started sparking and the battery was hissing and the car didn’t start after that.

so confused was just trying to fix my car for work. 2008 g37s coupe

 

Yikes
Any related codes?
did you test the old battery before replacement?
test the old alternator output before replacement?
Test the new components?
Still have "smart charging" enabled?
Ever have the software updated?
Route the ground(s) through the amp sensor?
Check the cables for shorts or breaks?
Did you buy bargain or quality parts?

 

I bought a new battery and a used alternator, no lights on dash just tpms light, but after the alternator sparked I checked the alternator and the back wire with the bolt was loose, I tightened it and charged the battery and tried to start it and it was just be clicking from it sounds like the ipdm box and negative would give of a little spark and the battery would start hissing right after.