Need AC help

Anyone ever see this? scanning a 2000 Silverado PCM. I am trying to get the idle to bump up when the AC is on. Looking in the scanner and when 12 volts is applied to c2 pin 17 (red 17) AC requested stays at "NO". Same thing on 3 PCM's, all 2000 silverado's. Tried scanning two 2001 suburban PCM's, when 12 volts applied, AC requested says "YES" on both of them. System options are identical.
The PCM I am using in my swap is one of the 2000 silverado PCM's and has the correct tune in it. It will not bump the idle up to the "IN GEAR, AC ON" value. I am getting 12 volts when AC switch is on at pin red 17, I have grounded the low pressure switch wire at red 55, grounded the high pressure switch at red 11 and nothing. Is the AC request location different on the 2000 Silverado than the 2001 suburban? Any ideas?