Voltage bounces from 12 to 14...

[astrochimp]

When starting car...sometimes the voltage stays at 12v until you rev it a bit then it jumps to 14v. Other times it will bounces between 12-14 at idle.

Also, sometimes when I come to a stop it will drop down to 12v. If I understand correctly, the voltage regulator determines when the alternator 14v is activated.

I don't think the voltage regulator is that old (could still be the problem) but is there another reason that would cause the regulator to jump the voltage around?

THANKS!

[72-CLASSIC_RIDE]

Battery strength would be my 1st thought and would investigate this 1st.  After that, Alternator, Voltage Regulator.  Also, depending on Alternator Voltage capacity vs. voltage usage during those blips would have a similar affect.  Those are my thoughts and sure others will add theirs................... Good luck and hope it's an easy repair.

Doug

 

 

[Dtret]

IMO. I don’t think you have a problem. My chevelle had done that forever and so has my 88 Monte SS( internal regulator). Like I said my opinion. 

[astrochimp]

is this a Member Here?

This looks like a good idea. 

 

[astrochimp]

Actually, since my alternator is pretty new, this ELECTRONIC voltage regulator is what I'll be getting. 

https://www.autozone.com/batteries-starting-and-charging/voltage-regulator/duralast-voltage-regulator-vr715/130005_0_0

[Blake350]

before I checked your link I said "i wonder if hes going with the wells vr715...seems to have gotten pretty good reviews...please post the result and how you like it...Thx!   

[71MonteCarloMD]

From what I learned that external voltage regulator should be replaced when you replace alternator.  So yes do get that replaced as I got mine from Napa for 72 GMC C15.