Hi:I've been through all my different PMDG 737 tutorials/manuals (stacks) and have not found the answer I was looking for. I know this has been discussed numerous times in the past but I cannot find it anywhere so please don't ball me out for it.I have no problem setting up the FMC for a flight. I can get everything to operate as it should except that crazy A/T switch. Just before I taxi on to the active runway, I try to "arm" the A/T and the light below just flashes red (meaning disengaed...right?).I know this means that I have not set something up right or definitely doing something wrong. Everytime, I'm at the hold-short line, engines are at idle but no matter what I do, I cannot get the A/T to arm. What I'm wanting to know is in what order do I set it?I hope someone can help me out. I would really appreciate it. Thanks for your time and help :-)Fletcher R.

Hello Fletcher:In order to arm the A/T - you need to engage the FD (Flight Director) switch. The FD switch is diagonally down and to the left when looking at the A/T switch.After the FD is engaged, you'll be able to use the A/T with FMC and the TO/GA switch (top left screw on MCP panel).Hope that helps!

Hi:Thanks for the help, unfortunately, engaging the FD first still did not let me arm the A/T, I'm also unable to make many of the "gauges" or "switches" work. I think my 737NG files are bad or some are missing, something is just not right like it used to be.I appreciate any other added comments/suggestions, etc...Thanks so much,Fletcher R.

Which gauges / switches give you trouble?Just out of curiosity, how is your overhead panel setup? Can you screenshot it and post it here?

Ok, sorry it took me so long to get back but anyway...I'm not good at screen shots but I promise, the overhead and mcp panels are set up and look just like they do in the manuals/tutorials.BTW...I did a complete re-install of the PMDG 737, AIRAC/SID-STARs and all as well.Everything looks good, sounds good and there are no warning lights of any kind, the FMC appears to be happy with all the inputs...it just won't let me arm the A/T, that dreaded little red flashing light just blinking in my face :( telling me that it has been disengaged when it was never engaged to begin with.Oye....I don't know what else to say or explain but I'm up for any and all suggestions. Thanks,Fletcher R.

Hmmm - I'm not real good with troubleshooting beyond this point - but, if you look at the Throttle Panel, there are two switches in the lower right corner that disengage some stuff to do with the AP - you haven't clicked that by mistake have you?Edit: right corner

The only thing that I can think of regarding this situation, is perhaps you did not turn the generator on in the overhead panel.

Hi:Thanks for that bit of information...that could have been it.I recently just did 3 flights back to back and the A/T worked every time I armed it. I don't know what I did differently, I guess that means I need to go over my checklist more carefully...good thing I'm not a real-world pilot or I'd be up to my eyeballs in "it" ;) Is there something in the OHD panel that if it's not on, etc... that it will not let me arm the A/T?Thanks again for everyone's help. I think about to narrow this done since it worked all day today but I don't know what I did :-roll Thanks,Fletcher R.

Check in the overhead panel and make certain your two generators are turned ON! If they are off, the AT switch WILL NOT ENGAGE.Regards,Stanner

I would just add to this, just to clarify, on the overhead panel it's the engine generators that need to be turned on in order to arm the autothrottle, not the APU generators.