If you have the Dometic Duo Therm 4 bottom control go to this link to download the manual and troubleshooting guide. Just know that the micro switches for the buttons over time get dirty and gummed up making it difficult to switch zones. I finally got tired of cleaning and messing with mine and upgraded to the 5 button control. You can buy refurbished 4 button controls on ebay.
Chuck & Teri, 1999 35 ft. Dolphin 5350, F53 Chassis with tag axle, Chassis build date 1/99 in Mexico, Banks System, Trans Command, Air Lift Air Bags on rear, Koni Shocks, Blue OX TruCenter, TigerTrak track bars front and rear, Roadmaster 1-3/4" rear auxiliary sway bar, 2013 VW Passat TDI SEL Premium, 1994 36 ft. Avion 5th Wheel. FMCA #F430129