The air compressor that supplies the air for the drivers seat as well as the exhaust brake valve prematurely fails over and over again. If the compressor fails the drivers seat will leak down and sit on the floor. All you will be missing is dingle berries from the visor. Today it's a bad relay, tomorrow it's a bad compressor. I had to tell the dealer to stop just changing the relay or compressor and check the duty time switch. The compressor runs a lot which causes it and the relay to fail. Once they determined that the duty cycle was too long they replaced the switch and would you believe the pump hasn't failed yet.