Rear Air Suspension

What is your question?

The compressor for the air shocks quit working, so I replaced the compressor and both rear air shocks as they were both leaking. After doing that I still cant get the compressor to come on. So I know there is a electronic leveler switch on the drivers rear, but how do i test it to see if it is bad? It's not a cheap part to go and buy. I'm told there is one on the passenger side too, but I don't see one, so is there one or not? Could it be a relay or something? Any help would be greatly appreciated! Thanks, langer in mn