big 3 ? voltage meter ****in crazy

[blackman 10+ year member]

alright I did the big 3 in my 88 chevy g20 and now the voltage meters rapidly jumps back and forth between 14 and 15 volts maybe 16 volts. why does this happen after I pass 15 mph Ive never seen this before? btw before i pass 15mph im sittin at like 14.6-14.8 volts

Click to read more...

 

[blackman 10+ year member]

oh and by the way i left the stock wire on the alternator to the guage, maybe thats y?

 

[AlterEgo99 5,000+ posts]

Your '88 is a bit old but I know in my '08 I have a voltage regulator loop that the ground wire from the battery runs through so the onboard computer can monitor and regulate the voltage...do you have anything like that? Maybe you bypassed it? Just a thought.

 

[93dakota 10+ year member]

I agree ....look for an external reg for the alt that you may have bypassed

 

[Compjake 10+ year member]

if it goes from 14 to 15 then i would guess at the speed you where going the alt was charging between 14.9 and 15.1 and just bouncing between the two.. that I would say is normal. 16 volts although is not normal unless you have a 16 volt setup, perhaps your voltage regulator is failing?