I have to leave for work in a few minutes, but I can give my observations to date.

1. Climate controls output +0-6VDC based on the location of the climate fan selector.

From the Crossfire Specialist Student Reference Book, page 202 (PDF Page 214), it has the following ranges in five stages.

Stage 1 = 1.1 to 1.8 V
Stage 2 = 2.0 to 2.6 V
Stage 3 = 2.8 to 3.2 V
Stage 4 = 3.6 to 4.2 V
Stage 5 = 5.0 to 6.0 V

On mine I was getting a bit over 7 VDC on Stage 5. Not sure if that is significant.

That voltage is then used as a kind of throttle reference in the Regulator and a proportional 0 to 12VDC output is produced. I do not yet know if it is a PWM system or something else. The search continues.