I tried to arm the autothrottle the other day on the 737-800, and it did not arm for some reason. On takeoff, I went ahead and tried to arm it so that way I could use the TO/GA button, however every time I tried to arm it, the button would automatically go back down and there would be an indication on the main panel that read A/D disconnect. What could be this caused from? Thanks

Please sign your posts.Silly question, but did have the F/D switched to "on"?

Most of the time when this happens to folks it's because they've forgotten to turn on the engine generators after engine start.

Well, during the execution of the checklist, when it says to turn on the engine generators, the generators are already turned on. Now, during shutdown, I have tried to trurn off the generators, however it seems like it is a spring loaded switch, so when I switch it off, it goes back to the on position. I have turned on the f/d as well, and still no luck on the autothrottle. ThanksJoseph DaltonPPL/SEL

Joseph,on the 737NG the engine generators do not connect automatically. You have to do that manually after engine start. The switches are indeed spring loaded so just move them quickly to ON so the "GEN OFF BUS" lights go out.Regards,Markus

I finally figured it out, thanks for all of your help. I did not realize that the generator switches were spring loaded, here all this time they always looked like they were switched on. Thanks againJoseph DaltonPPL/SEL