So I got my 350z a couple of weeks ago. Its a 2003 6 speed enthusiast edition with 111,3xx miles.
My voltage meter reading on the gauge pod this morning while warming up the car was in the high 14s amd while driving it on the freeway it was going up the the 15s almost near 16 volts. I know cars should read around 13 amd mod 14s but it from how it looked it looked like it wanted to go to 16. I had the stock radio on and heater on. When I arrive to work i let it idle and it stays around the mid 14s volt then idle drops to around 300 and interior lights go out amd motor wanted to turn off but it went back on to 800rpm. The only mods i have on this are exhaust, short ram intake, interior led bulbs and led license plate lights. Any idea what causes all this? I did a search but found lots of info on low voltage not high...

Second, i called a shop for a manual transmission fluid exchange and he refuses to do it only due to the fact that it had 100,000 plus miles and is not recommended because new fluid could potentially damage the transmission after a while.

Any help would be appreciated. Im still learning alot about this car

 

And i forgot to mention when i put in the ON position not start voltage reads normal around the 12s.

 

The 350z does not like certain LED bulbs, causes electrical gremlins. Change the fluid yourself if you can, only 2 bolts, run Redline MTF 85 or 90.

 

Not sure what to make of your voltage problems, but why not use your on-board diagnostic system to figure it out? Pulling codes from your ECM and BCM should help.

As for your tranny, you should take it to another shop or DIY. Any shop that says NOT to replace lubricating fluids after 100K is not one to do business with. Just be sure to use a good quality transmission fluid with a viscosity suited for the Z33 like Redline MT85.

 

Fluid is already addressed, just change it.


Voltage, what you need is an actual voltmeter on it. My car shows around 15 when driving, actual voltage is like 14.25ish. It's not really precision and no idea why Nissan put it there.

 

High voltage is usually a faulty voltage regulator. You should check at the battery with a multi meter.. If its above 15 go get it checked... Your battery is probably not happy about that situation and you will likely need a new alternator.

 

Update: So I just checked my battery usong the voltmeter and in the ON position it read in the high 12s. And while its idling it read high 13s - low 14s, but on the Z volt gauge it shows high low to high 14s I think hard to tell when theres no 15.

 

Yeah were in the same boat. But i did end up using a voltmeter amd found it was lower than the gauge showed