Hi guys, I started having problems about 8 months ago when my 2008 350z hit the ~110k mile range. After driving on the freeway and exiting on a red ligh , I noticed that on the "volts" window on the dashboard, it would move from about 16 to 12 and then back to around 15-16. I figured it was my battery so I bought a new one and it still had the same problem, so I bought an alternator the other day and installed it today, and noticed that after driving on the freeway and stopping on a redlight, the voltage never moved BUT on the end of my drive while I made a right turn into my driveway I noticed it move again from about 16 to 12 volts and then back to about 16.

Have any of you experienced this issue? I am installing spark plugs next week if that helps at all. Thanks guys

 

forgot to mention that i also changed the alternator belt today if that helps..

 

sounds like a gauge issue, the voltage reg is in the alternator
or mayby amp, the white box behind/below the radio

 

went to autozone to check it again, they said my battery and alternator are working fine.

 

Does the voltmeter needle deflect from g-forces? i.e. are you turning into your driveway fast/sharp enough to have that be the cause? In my old Alfa Romeo's, this does actually happen with some of the gauges, believe it or not. Another option is that perhaps some part of the car is moving and partially shorting a wire, causing a temporary voltage drop. Just guessing here, so take this advice with a grain of salt.

 

Your fine dude , most likely the crappy gauge crapping out . Same thing happening with my oil pressure gauge right now . The needle just does as it pleases

 

Bump