Okay, I've never had to replace an alternator so I don't know a whole lot about them but I have done some researching. The battery is brand new it's the autozone gold brand. It tests at 12.67 cold. When started cold I get 14.67 solid. When warmed up and with everything loaded (wipers on, lights on, heater on full blast, rear defrogger on) I get just about 13. Does this sound about right ? I have no vacuum leaks and base idle is a perfect 550 but when I got my lights on and the car is fully warmed up the idle seems to hover at around 1. I'm confident that its related to my egr solenoid and/or vacuum control that's messing around and I will be getting those parts in the next couple days.

I'm just not sure what my volts are supposed to be with everything fully loaded.

 

Peronally I like to see something around 13.5 but how much does the .5 really matter,,,,are you having issues?

Also not that good with swaps, but base idle should be in the 750 range, at least with a stock f series.

 

go back to autozone, and get a free charging system test on the parking lot...

that load test will rule out if your alternator is on it's way out... how's the belt tension/ condition?

 

I don't remember what it should be underload. 13V running underload should be good IMO. Now, the question is... how much peak amp can the alternator put out? All the Alternators I tested usually puts out 80amp and up. Highest I've seen is 135amp on a VW.

Why do you want to know how much put out under load? You never stated what symptoms the car gives.