Okay, so here's the scoop. I installed the new Powermaster 140 amp alternator. Yeah, not quite bolt-on. Nothing big, the output lug is larger than the stock alternator, also, the mounting bolt is standard thread, not metric like stock. No big deal, a Dremel tool and a trip to Home Depot fixed those problems.
At idle Tlink shows 13.6 volts. That's a good thing. Took the car to the street. It ran rough at first, but within 5 seconds the problem cleared up. Pretty much the same situation as when I hooked up the battery charger. It's funny, I've been a GN owner for over 16 years and have never seen voltage cause these kind of problems. Then again, this is the most heavily modified I have ever had a GN.
Making short trips near the house all was well. I decided to make a longer trip, this is where the problem started. About 8 - 10 miles into my runs with the new alternator the Voltage idiot light comes on. I'm able to drive home without a problem. I've got the vacuum brake conversion, and my brakes seemed very soft after this happened. My I was hyper-sensetive at this point just hoping to make it home.
Anyhow, I get home, opened the hood, and what do I see? The alternator belt was gone (belt had less than 150 miles on it!) I heard no noise to indicate I had lost a belt! The AC belt was also twisted 90 degrees, I figure the Belts came in contact upon release. After installing a new belt it looks as if the Powermaster pulley wasn't quite right. They say it will work with belts up to 10mm, but the pulley seemed to wide for my taste.
I've swapped out the Powermaster pulley to a stock pulley and have yet to road test it. I have had a chance to run it in the garage though. When I run the car for only a minute or less the alternator belt is much hotter than the other two belts!
Alternator alignment seems correct. I guess I'll just have to take it out again and see what happens. The last belt didn't wipe anything out, I can only hope that if the same happens again, and I don't lose anything!
Now I have to figure this situation out. Also, my Manifold air temp is showing up at -58 degrees on Tlink. I have Casper's sensor and wiring kit, I'm sure the sensor is good, so I have to check my wiring at the ECM.
Thanks for your help guys! I never would have looked at voltage to solve this problem!