... to about 10volts under hard acceleration. When you get out of the throttle it goes back up to ~13volts. Anyone ever experience this? Anyone know what this could be?

 

I would probably confirm that you have clean, tight connections with the battery and the power and ground terminals on the passenger shock tower.

 

if these are good, sounds like the alt has low output at high rpm

 

belt tensioner going bad , belt slip

 

I think so far I am going with low out put at high RPM, the altinator is prolly starting to go. :/

 

Before you buy a replacement alternator, I suggest that you take it to Advance Auto or Autozone for an alternator testing. That way you don't throw parts at it.

Mike

 

I did and it was like .5 volts low or something stupid like that. Which is I why I said it's prolly on it's way out.

 

would low output really cause it to drop that low(10v), wouldnt it drop to somewhere around 12

 

still say it sounds like a slipping belt

 

thats a possiblity

 

The belt is only about a week old.

 

Was the tensioner changed with the belt?

 

My bet is on the tensioner.

Do you have a voltmeter?

Engine running tests:
Set your voltmeter (DVOM) to Volts DC. Put one terminal on the negative battery clamp and the other somewhere on the block... you should have 0V.

Put the DVOM on the positive clamp and on the hot lead coming out of the alternator... you should have 0V.

Put the DVOM on the negative clamp and on the hot lead from the alternator... you should have over 13V

There is a possibility you may have resistance in one of your connections, cables, etc. But, with RPMs and voltage dropping, it could be that the alternator is slipping... check the tensioner. Especially if it is a high-mileage engine.