There in a new piece of service literature that has been produced by Honeywell that is a complete "In-The-Field Tool" for servicing their economizer controls. This piece of literature is titled Economizer Check-Out Procedures. Literature number 63-9730 dated February 2009. For those who service A/C units that have economizer I would suggest that this pocket size service guide would be very handy. For clarity purposes I must state that I do not work for or work for a supplier of these products. It is just a handy piece of literature that could be a valuable assit to some service personnel.