5.22 Are both of the autopilots like the Lear?

From FlightSim

The Lear doesn't need arming, but the 737-400 type does. The switch to the left of the autopilot master is the arming switch. Once it is on the speed can be selected. Maybe you already know all this, it sounds like you are trying to do things with your instruments that I wouldn't even attempt. I've also experienced some of the instruments being turned off for some reason. The heading readout is one. Nothing having to do with heading will work until I turn it back on. You might look at the instruments under Aircraft Settings.

Bob Fiedler