Alternator Wiring

[trev1]

I know this has been beat to death somewhere..........

I have a 69 CST C-10 originally a 396 BB.

Put a 350 with a NP A-833 3 speed OD trans. It has the serpentine conversion on it from a 97 Z-71.

I have to move it today!!! I have lost my shop space and it has to come home.

I cant get the alternator to charge.

I need help ASAP!

The alternator is a Dura Last gold # 1650 (pic)

And the pigtail that plugs into the alt has one wire that corresponds to the "L" marked on the Alt.

How do I hook this up to get it to charge?
Here are a couple of pics that might be helpfull.
The guage and the Starter Switch

I cant get the pics to all load but I am using a standard AMP Guage bought from the parts store and the starter switch has the OEM wiring.