i replaced my altenator as it failed the altenator test both with my own meter and the shop altenator test, once i installed the new one it ran great at 14.01 right on the mark, however i gave it some gas and the volts spiked up to 17 something it only did so for a few minutes and now its running fine again. is this something i should be worried about or was it just the computer needing a few minutes to re regulate the new altenator?

 

Probably just a fluke. Pay attention to it, but, don't worry overmuch.

 

ive been paying attention, its been holding just fine aside from those first few moments

 

That's worrisome but will be difficult to diagnose as long as the symptom stays hidden.

In a nutshell, the regulator switches the ground of the field winding on and off to make the alternator switch between providing current and not providing current. It switches on when measured B+ is 0.5V below the target (13.7V) and switches off when B+ reaches 0.5V over the target (14.7V). So if you saw 17V the regulator failed to interrupt field winding current, which indicates a problem.

Most likely, because it went away on its own, it's a flaky connection somewhere. Recheck the small wires leading from the alternator to the PCM carefully, and clean the contact surfaces of the connector. A bit of dielectric grease is a good idea, as it'll keep corrosion from forming to bite you later.

 

thanks alot for the explanation on that, i didnt know thats how it worked, ill recheck the connections in a few days here. my old altenator would hold at about 14.6-7 this one stays right at 14.01

 

had a chevy bought a yellow top optima batt and reman alt , changed em both out and the reman alt cooked the optima battery gell was seeping out the top of the battery , had parts store check the alt and it pegged thier meter off the charts ,guy said he never seen anything like it, they gave me new battery and a "new" alt in replacement, just a thought but im sure your good