OB does not make a control for the condenser/compressor units aka the split units. They do make one for the self-contained units which as Ralph said require two or three aa batteries when they wear out. I just replaced two units on my boat one split , one self contained. To wire the split; I completely removed the OB harness and then wired my old SMX control directly to the hi press switch/ lo press switch and the compressor. There only three wires to the compressor: R,C, and S and two each to the switches. If you have SMX there are two boxes one is Hi voltage , one is low . The box toward the compressor is the Hi . Smx wall control is wired in the low v box, as is the remote thermistor /temp sensor they are marked on mine. The Hi v box has your pump, blower, and ac current in connections on a terminal board, the positions are marked inside the cover and on the TB. If you don’t have the old split still intact ,check one of the others onboard to be sure you are wiring correctly…..Hope this helps………………..Pat