Lower voltage from alternator

[MStokes]

Replaced the battery in my car with a smaller one that was on sale(625CCA from 800CCA). Alternator used to put out 14v, now it show's about 13.1v. Is this normal for a smaller battery or is it time to look at new alternator? Broke the post on the old battery.

[gonzo4191]

when the car is running, you should see about 13.3-13.8....so it's a little low

have any problems starting?

[MStokes]

Hey gonzo. Alternator seem's to be doing better. Run's around 13.4 in day time & 13.7 at night. Used to run 14.3 all the time but I think battery had issues.

[01bonneSC]

14.5 - 14.7 is what Im at and my bat is new from January. Thats what it has always been at.

[Jrs3800]

You guys need to be careful with what you answer and how you answer it... The systems on these cars are different... Cold start for the Series II bonnevilles for 95-99 should be right about 14V... Once the battery is charged the system should run right around 13.0-13.5V would be very normal with these alternators.. The Delphi and Denso units on the newer Bonnies will put out 14+ all of the time..

[ChilinMichael]

Yup, I did a mod where the voltage sensor is now external like the 00+ and reads from a 12v line that's part of the car, my alternator in my 95 now does 14+ at all times. Without the mod, our cars run lower (13, etc)

[MStokes]

Hey friend's, mark here. Alternator is back to running 13.9 to 14.2 all the time again. Not sure why but happy for now Will clean cables good this weekend just to keep my old buddy happy. (car that is)

[ChilinMichael]

Yeah when you see random voltage changes, it's certainly a good idea to check all cables and clean them. Don't forget the 3 main ground points too under the hood.