82 RX7
My car will charge only when idling.If i turn anything , ie. headlights,wipers heater,or hit the brakes or turn signal,the ammeter goes way down...When driving,the car seems to NOT charge and seems to draw more power from the system as i accelerate...I took the alternator to a shop and they said it was outputting 13.8 volts.they said it was fine....Is there an outboard voltage regulator somewhere...Right now, I have to let the car sit idling with nothing on so that the battery will charge back up...I need some advice ......THANKS !

 

Battery cables need replacing; with a solid clean ground.

 

Is your alternator stock? If it is that's your problem, stock alternator is a wimpy 50-55 amps. Also they are internally regulated. easiest fix is pick your self up a second gen alt. same hook up and it's 70 amps. If your gonna run a huge stereo system then upgrade to the GM100 amp. There's a few write-ups for that just use the search.