I have noticed that my idle goes way low when I even lower my power windows. Would this be a bad battery? bad alternator? bad ground?
It also happens when the radiator fans kick on.

Thanks

 

i would check all three, but it sounds like a bad ground or alt to me. perhaps a battery cable is mostly pulled out of a crimp?

start the car, let it idle, and turn off all accesories. What is the voltage across the battery? were looking for about 14.5v
then turn on as much stuff as you can, rear window defroster, blower motor, etc etc. what is it now?

does it do the same if you turn on the A/C?