The best Dash A/C recharge valves to use are the ones at the rear of the coach. One is accessible from underneath and is by or close to the frame rail on the right side of the engine and the other is above it and it is usually best or easiest to see or find when accessed from the top through the engine access door in the bedroom.
Lift the right rear (right when standing behind the coach looking forward, of course) bay door for better light and one of them should come into view (cannot remember whether it is the red or green one, sorry !). The next challenge is to know the pressure that is required to recharge the system. My coach and A/C pressure notes are not close by, But a call to BCS in Bend, OR might be the quickest for you. My cost to recharge the dash A/C was $150 to hook up the machine and maybe $50 for freon at a Truck shop. The process takes some time, even if no leaks are found. Good luck with the recharge.
