NST Pulley Set Alternator Issue - Page 3 - Toyota Yaris Forums

CTScott · 04-12-2010, 02:28 PM

Quote:

Originally Posted by rob323

If the Scangauge is still showing over 13 volts, how can the alternator be "under-charging" the battery?

For a lead acid battery, the optimal charging voltage is 2.26 and 2.36V/cell (which = 13.56 to 14.16 Volts).

MGargano · 04-12-2010, 07:05 PM

Quote:

Originally Posted by CTScott

For a lead acid battery, the optimal charging voltage is 2.26 and 2.36V/cell (which = 13.56 to 14.16 Volts).

I'm confused again, since I'm getting 13.5-14.2v, according to the Scan Gauge. Is this too low? Or is it the fluctuation regardless of load that's the problem?

CTScott · 04-12-2010, 09:33 PM

Quote:

Originally Posted by MGargano

I'm confused again, since I'm getting 13.5-14.2v, according to the Scan Gauge. Is this too low? Or is it the fluctuation regardless of load that's the problem?

As long as it isn't sagging below that then you are probably OK, but the alternator and regulator should be able to maintain a steady 14.1 at idle.

MGargano · 04-12-2010, 09:41 PM

Quote:

Originally Posted by CTScott

As long as it isn't sagging below that then you are probably OK, but the alternator and regulator should be able to maintain a steady 14.1 at idle.

It's definitely not maintaining any kind of steady voltage, at idle or while moving and regardless of the absence or presence of a load.

I guess I'll just swap the alternator and see what things look like with the "new" one.

MGargano · 04-17-2010, 05:43 PM

I swapped the whole thing today with an '09 alternator with around 1,000 miles on it ($70). No change in voltage; it continues to fluctuate regardless of load and at idle.

When moving at a decent speed, it generally holds at 14.1v, but at idle and slower speeds, it fluctuates from 13.5-14.1.

MGargano · 04-22-2010, 01:55 PM

Well after no change in voltage with the new alternator, I decided to do the "Big 3" upgrade.

I ran 1/0 wire from the alternator to battery +, and chassis/engine to battery -

Zero improvement. Everything is exactly the same- voltage still drops to, and fluctuates around, 13.5 at idle/slow speeds and holds steady at 14.1 as long as I'm moving at a decent speed, all regardless of load.

Hooray for wasting time and money.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
NST NonStopTuning Pulley Kits	NonStopTuning	NonStopTuning	19	11-08-2014 11:23 PM
FS: Blue Pulley Set	Shijima	Items for Sale by private party	12	09-18-2009 09:34 PM
NST (NonStopTuning) Ebay Feedback & Rating	NonStopTuning	NonStopTuning	0	07-19-2009 11:11 PM
Feeler: NST 10% Underdrive Crank Pulley - Gray	Black Yaris	Items for Sale by private party	10	04-29-2009 12:24 PM
NEW GROUP BUY: NST WP-Lite & ALT-Lite Pulley Kit (NonStopTuning)	NonStopTuning	NonStopTuning	266	09-29-2007 03:51 AM

04-17-2010, 05:43 PM	#41
MGargano Drives: 2009 Yaris Hatchback Join Date: Feb 2009 Location: NJ Posts: 792	I swapped the whole thing today with an '09 alternator with around 1,000 miles on it ($70). No change in voltage; it continues to fluctuate regardless of load and at idle. When moving at a decent speed, it generally holds at 14.1v, but at idle and slower speeds, it fluctuates from 13.5-14.1.

04-22-2010, 01:55 PM	#42
MGargano Drives: 2009 Yaris Hatchback Join Date: Feb 2009 Location: NJ Posts: 792	Well after no change in voltage with the new alternator, I decided to do the "Big 3" upgrade. I ran 1/0 wire from the alternator to battery +, and chassis/engine to battery - Zero improvement. Everything is exactly the same- voltage still drops to, and fluctuates around, 13.5 at idle/slow speeds and holds steady at 14.1 as long as I'm moving at a decent speed, all regardless of load. Hooray for wasting time and money.