alternator voltage
 

Hi all:

I have S4 but this should probably apply to all models

I would like to know the voltage you are supposed to get with the stock alt (if you have S4, if you could just look at your gauge and tell me what it says)

when all the following accessories are on:

headlights (low-beam)
heater vent all the way (no AC)
rear defrost
stop light (brake pedal depressed)

at idle (750 rpm)
and at about 2,000 rpm

I am personally getting 12 volts at 750 which may be ok, but I am getting 12 volts also at 2,000 rpm, which is bad.
As a reference point, I am getting 14+ volts at idle with no accessories.

thanks for your time,
hugues -

It should always be at least a little above 12.6 volts, anything under that and you are running on your battery.

The Alt, in good condition with all the acccessories on that you mention you should see around 13.5 volts at idle.