volt droping
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
volt droping
New pwrmaster 100 amp 1 yr old, battery checked okay, voltmeter dropping slightly upon increasing rpm's ??. I had the alt checked and it was putting out 13.9. What too do???? 
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
Re: volt droping (BatManFire)
its a powermaster from summit. rated 70 amps at idle with a max of 106 amps. It used to supply a greater voltage per my guage at idle now it is below the middle. When lights are on with a/c the needle points to about 11 oclock and even less when directionals are added and foot on brake. I'm just waiting for the battery to die but it tested out okay with pep boys?? Iknow its drawing down power because I can hear the fan blower slow down at a stoplight.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Re: volt droping (dogboy)
Somethings not working right dogboy. 13.9v is minimum for a 6 cell (12v) lead acid battery to charge. And voltage should increase with rpm from 13.9 which is nomial 12v battery voltage to over 14v - not a lot but enough over 13.9 to force the recharge. If its a one wire alt it should read only battery voltage at idle and 14v+ at a few hundred rpm more.
It doesn't sound like a short (to Ground) or voltage would be low all the time. I'm guessing a bad connection from alt or an open wire somewhere from the alt? Yea, try a jumper all the way from alt output to battery positive (lift the normal of course) and measure voltage again. BTW have you double checked the readings with a multimeter? Maybe a bad installed voltmeter?
Happy hunting. cardo0
It doesn't sound like a short (to Ground) or voltage would be low all the time. I'm guessing a bad connection from alt or an open wire somewhere from the alt? Yea, try a jumper all the way from alt output to battery positive (lift the normal of course) and measure voltage again. BTW have you double checked the readings with a multimeter? Maybe a bad installed voltmeter?
Happy hunting. cardo0
