Alternator charging too much?

[RustyBuckets]

Hey, so ive got an 85 k10 with a 79 350 and i replaced my battery which i feel died prematurely with a new one and i noticed it seemed to be boiling over the battery acid. So I checked the idle voltage and its charging at 14.9v. It seems a bit high but do i need a new alternator?

 

[Honky Kong jr]

Hey, so ive got an 85 k10 with a 79 350 and i replaced my battery which i feel died prematurely with a new one and i noticed it seemed to be boiling over the battery acid. So I checked the idle voltage and its charging at 14.9v. It seems a bit high but do i need a new alternator?

Probably just the voltage regulator. A bit cheaper then a new alternator

 

[1987 GMC Jimmy]

15V? Yeah, I think that’s too high. If you have an alternator shop near you, have them put in a new regulator. $25 where I’m from for parts and labor.

 

[hatzie]

14.5v is the normal good charge voltage. Is your meter accurate? 0.4v may be in tolerance for some cheaper meters.

Does the voltage rise higher when you open the throttle or stay stable?

If not I'd try another meter or two before condemning the alternator.

 

[RustyPile]

13.8 - 14.2 is spec for that alternator.. 14.5 is just barely below boiling.. Why buy a complete alternator when a new voltage regulator will take care of it.. Good advice @hatzie

 

[4WDKC]

If you have any plans in the future for electric fans, winch. stereo system something else that draws a low of power you may want to upgrade the alt to a higher amp.