voltage across battery when charging ?

[Unit 5302]

Just as an FYI, much below 12.3 volts, the battery probably won't have sufficient voltage to start the car.

12.4-12.6 volts is considered charged. 12.3 is pretty low, and 12.2 is discharged. Below 12.2 is pretty much dead and you shouldn't expect the engine to crank.

The only place I can think to check is at the union of the main power lines off the alternator. While two positive leads run off the alternator, they merge into one 10gauge wire, if I remember right (been a long time). That connection can get severely corroded which can definitely lead to low voltage coming from the alternator.

I apologize if this was already suggested, I didn't read the whole post.