DMPesso

I have an 01 GS430 and I wanted to know what my altenator should be testing at because when they replaced my battery they said its low at 12-13 volts but they changed the battery anyway. When I looked in sewell for a new altenator it says 12v altenator so shouldn't mine be fine? What should it be running at ? Thanks guys

Mr Jokster

iTrader: (8)

At idle it should run anywhere from 13.8v up to 14.4v

DMPesso

Is it possible for a defective battery to have the alternator running at only 11 to 12 V because now that they changed the battery the car does feel much better but I'm not sure if the alternator is still bad. Is it possible to read low because of a bad battery but then charge itself back up or does the alternator and battery not affect each other?

DMPesso

With the new battery the car is starting much better it feels stronger that's what's making me think the alternator isn't bad. I just wanna know if it's possible for an altenator to read low because of a bad battery but after changing it is it possible for the alternator to go back to normal?

Mr Jokster

iTrader: (8)

If the battery isnt accepting a charge, the alternator will have to work harder which will create low voltage due to a large draw from battery. The alternator is supposed to sustain the batteries voltage and fill it at the same rate as the car is taking, if the battery is dead, then the alternator will stay wide open and struggle and this can and will cause the alternator to go bad in time. Just think of being on a treadmill and just strolling, thats how the alternator should work, but if you turn the treadmill up and you're at a constant sprint, you're eventually gonna weaken and struggle until you pass out.

DMPesso

Ok cool thanks im still gonna go to autozone and have them check it anyway but it definitely feels better and I never got a battery light and I know when the altenator is bad you usually get a battey light

Mr Jokster

iTrader: (8)

I dont know about that. I wasted an alternator and it was running at 10v and I never got a battery light.

DMPesso

Oh ok well then I retract that statement lol