Autopilot won't engage?

[737guy1 39]

I'm sure I am just missing something here.  I am in-fight, have the master autopilot switched on on the captain side panel, have an altitude selected in the selector.  I can activate the FD for all modes, but when I hit ENG in the middle, nothing happens.  What am I missing?

 

Thanks!

[737guy1 39]

Nevermind I figured that out.  It was the Pitch Trim Switch.  I had not switched it to primary.

 

Still can't get VS mode to work on decent though.

[nachezdc9 25]

Remember to push the "arm alt" to arm an altitude in the autopilot before push any vertical mode or will not work.