One thing that drove me crazy when I first started trying to work on them is all the switches are overwhelming. Believe it or not (and I don't think I was alone in this) it took me quite a while to understand (nobody told me) that basically the switches have to change state. So for instance if you have a closed switch, when you pull in the actuator it should ALWAYS open. If it's open, it should ALWAYS close. So simple but so hard to understand, once I caught that the rest got much more simple.