I am installing a set of retracts into a cessna 421. I have the retracts on the plane but do not have a clue about the the plumming. The retracts a generic HobbyCity W/O Directions. I think I can figure most of it out but it has a three way air control switch. Can someone give me some suguestions on how to mount this. The only Three way switch on my radio is for flaps. (Spectrum DX 7). Pictures are worth a thousand words.