When I measure the voltage across the battery with the car off it's 12.8ish (normal), then when I start it it dips to about 12V. It doesn't actually go up to 14 volts until the car is fully warmed up. Is there something going on with my electrical or is this normal? I ordered a new serpentine just in case it's a slipping belt til it gets warm but by just looking at it it seems everything looks good. I also ordered a new voltage regulator just in case. Pretty sure it's not the alternator since when it is warm it acts as a normal alternator would when driving and under load.

 

I haven't tested it, but it seems to be temperature dependent

 

Yea I figured as much. I just had the problem of driving to wok in the morning bumping my stereo with the heater on and when I got to work my car was acting crazy and died that's when I decided to get the voltmeter out. Seems ok, but I want to check my readings against others.

 

Check the resistance on your cables.

 

On the display on my AFC Neo, it usually reads somewhere close to those numbers.

 

no way! thats not good mine is at 13v with car off and 14.3 with car on. reading from my turbo timer.

 

When your car is fully warmed up ... and you shut it off and then restart it, does it still do the same thing? Wondering if this is a temperature dependent thing where the ecu doesn't burden the cold engine with alternator load until it's fully warmed up or something!??

 

Yea I'm confused still too. My voltage has been good for the last week. No 12v when the engine is running. I figure its the rectifier or the regulator in alternator so I'm gonna monitor the voltage for a while and if I have anymore problems I'm gonna do a rebuild of the alternator. Thanks guys for your input/concern.