I finally installed a on/off/auto switch for my A/C.  I get tired of the compressor cycling on and off while the truck is idling and now I have control of what vent selection it is on and off. While I was at it I decided to put in a switch for my lift pump.  It is only used for priming and I didn't like the idea of the hobbs switch.  I had no control and no indication if it was on.  So, I simply disconnected the wires from the hobbs switch and installed an illuminated toggle switch.  I didn't want to drill holes in the dash, bezel or anything else so I made a bracket and it attaches on 2 existing screws that secure the kick panel. I am happy with it so far. 

A/C should never cycle at an idle this means your low on freon. Check your A/C pressure on both hi and lo sides. Mine is solid on all the time and never cycles typically.

Mine will cycle if I have the defrost and floor/dash on. I think it's floor/dash any way. Stays on solid with the ac on though.