superstingray77

Team,
Amongst the overheating issue in my other thread I need to get voltages up at idle where they should be, at least not in discharge around 10-11v at a 950rpm idle. I installed a Mondello 1 Wire Chrome 100amp alt 5 years ago and frankly it stinks. I have 4 guage grounds, 4 guage powe lead from it to the car and an Optima Red Top. At idle it wont even keep up with the the dome light much less fans, ac, headlights etc. At night under full load im down to 10 volts at idle. It will finally hit 12.5 at 1500+ RPM. So heres my thought.... Shouldnt I be able to convert the unit back to a 3 wire setup by installing the 3 wire 100amp voltage regulator back into it? The diode trio remains the same regardless correct? Thanks again for the help... btw I even tried the smallest pulley I could find on the alt.
BWD - Voltage Regulator

Part # R291

joe_padavano

I remain mystified by the attraction of "one-wire" alternators. In any case, yes, swapping the regulator should convert it to a conventional GM SI-series alternator.

superstingray77

I dont get it either, the 1 wire wasnt mentioned to me in the description when i purchased it so I was a bit ticked off when I opened the box I called them and they said oh just dont use the other 2 wires and it will work great. (as long as I am doing 20mph) I prefer the 3 wire setup any day. Honestly what does 2 small wires save??? You have to run the charge wire up to the alt in a harness anyhow. thanks for the confirmation. Conversion takes place tonight :-)

TripDeuces

1 wire alternators require you to rev the engine to about 2k rpm to energize the alternator. Then it will put out just fine at low rpm. Yeah they are a pita otherwise

superstingray77

I can see that on the guage, but then mine drops back to zero output once idle sits around 900 for more than 30-40 seconds. So constantly having to bump neutral and race the motor. Just not worth the hassle.

TripDeuces

Are you running a large diameter pulley on the alternator?

superstingray77

Swapped it down to the smallest one I could find to spin it faster. Made now charges at 1500 vs 1800 RPM but still weak overall. also tried removing the Mondello underdrive on the crank and installed a stocker there with the smaller pulley off my Stingray on the alt, it still wont charge or hold under load unless im over 15-1600 RPM

joe_padavano

Doesn't matter. The SI-series alternators require the resistance of the idiot light (or an equivalent 35 ohm resistor) on the "third" wire for the regulator to turn on and for charging to start. One wire alternators are notorious for not charging at idle.

superstingray77

Team,
Converted the Powermaster 100amp 1 wire back to a 3 wire by changing out the regulator. I now have a solid 13 at idle under full load and 14v just off idle. Best 25 bucks I ever spent. Borg Warner p291.