OK so I have this RTU, a Lennox (I forget the model # I think its a GCS 20) . I get a call the other week saying that its not cooling. Well I get there and neither stage will run when the unit calls for cooling. So I trace the problem back to the econimizer it will not open. So I trace voltage to the E control itself but no voltage is coming out of the Controller so I chage it. Boom now the econimizer works. Then all the sudden it stops working right in front of me, it wont even open when I set the minimum position to maximum. So I figure maybe (because its a little in the shade) its just cold enough to "lock out" the econimizer. So I go back the next day (now its warmer) and it works fine. I install a couple fan cycleing switches cause its cooling a server room 24/7 and I figure "hey low ambiant control may be a good move for this unit." Well I leave and about a week later I get a call again about the same unit. I get there and the Econimizer is not working again even when I mess with the Minimum Position (and its a pretty nice day'bout 60deg sunny and dry as a bone). It's a Honeywell Econimizer package, you know the type, Simple Enthalpy Sensor, Enthalpy Control and 24v Spring Return Moter. The light on the Enthalpy Board is on signaling that it is getting a signal from the Enthalpy sensor. Any clues as to why this POS will not worky worky?