[HoosierDaddy]

Ok I found it. Thank all who responded. Clint put me on the path. There IS an air modulator after all. It was hidden behind a trans cooler hose. It is operated by an air signal provided by an air pressure regulator and a 12 volt air solenoid valve. The schematics I had found for an air modulator were all linked to an air operated accelerator pedal. My accelerator pedal is electronic. I also removed the "automatic" air supply tank water eliminator and routed a 1/4" air line into the rear fender well capped off by a manual ball valve. Thank you , Richard for that idea!! I have gone from the air compressor running every 30 minutes to..........well I don't know. I run out of patience after an hour!