Yes, that is the black sealed box. It operates the throttle and the cruise control and the transmission and the pac break and, and, and. And you do not want it to go bad. They are totally rebuildable and not available new. As far as I know they are the weakest link in the whole coach. I also wonder if it is the reason that you can buy Dynasty's with 50,000 miles for $25,000.

The manufacturer actually told us that they don't know a thing about them. Thank God for Steve. Good luck.