Is a 03 350z 6spd. No mod expect for Injen CAI and JWT clutch and flywheel.
The car drives fine and no cel. Battery is brand new, like 3days. (It use to do it as well with the old battery) I though it was the battery.

Tonight when I went to start up the belt squeeze a little. Battery seems kinda low on 13volt. As soon as I turn off the heat. The belt noise stop and battery volt back to normal, but it still dies on moving...
When I am in gears is fine. When I shift to N, it sometime dies, moving or not. When it die out I was able to start back up right away. Any clue?

 

How many miles on that 03?
I'd check your cam position sensors.

 

^ what he said, but i would change them out regardless, prob wouldnt hurt to do the belt either if it is sqeauling

 

+1 on the cam and crank sensors.

Also check SES

 

car has 66k

 

Dude, don't throw parts at a problem. Get a proper diagnosis. You can bench test your sensors to see if they're bad. Replacing perfectly good parts with new ones because it "might" be the source of the problem is bad juju.

Start by checking the condition of your belt. If it's frayed or glazed, replace it. Then check the pulley on your alternator. Is it stuck or hard to turn? Bad belt plus low voltage could mean a problem with the charging system (i.e., alternator). Again, that's easy to get checked (most decent OBDII scan tools can do live diagnostics of your charging system).

If you're completely lost, take it to a professional. If you keep throwing parts at your car, you're going to end up poorer and your car still won't work.

 

What are the codes your car is throwing?

--Spike

 

Both belts were replace ~8k miles ago (oem)

It doeskin throw any codes. I have an obd II hook up and scan it when the car dies. It doesn't show any code. It seems to do it more often. Before is every so often. Last night When ever I shift into N. I Can see the RPM slowly dropping and car dies out and able to start it back up.

 

Stop putting it in neutral?

Have you checked your intake/piping for leaks after the MAF?

Crooked hose clamps etc could cause it.