Problem with configuration/startup of Garmin GMC 305

I'm replacing Chelton Glass with the Garmin G3X and Garmin GMC 305 Autopilot. I believe I have all the wiring correct. I have 12 volts between pins 7&5 on the GMC 305 unit; 12 volts between pins 9&10 on each of the pitch and roll servos. RS232 connection between GMC305 & MFD wring-out. RS232 connection between GMC305 and roll servo wring-out. I've configured the RS232 #1 port on MFD to "Garmin Instrument Data" and set the GDU 370 Autopilot to "Pitch + roll". When I push the "AP" button the autopilot does not engage. No AP information on the PFD: nothing.

PS. The can bus appears to be working. The PFD is seeing the servos (serial number information of each servo is showing up on the AP configuration page on the PFD configuration page). I have GDU 37x software version 8.9 installed on the PFD and the MFD

Anyone have a proposed next step?

Welcome Abe,
I have checked my spreadsheet and it looks like you have it wired correct.
Are you getting the indicator light above the A/P button when pressed?
Have you checked your GSU indicator light to make sure you have a good Can Buss?

The Servo also has a LED to show communication with the Can Buss.

Mark,
No, I am not getting an indicator light. Actually I was wondering if the GMC 305 unit is bad from the get-go. Yes the GSU indicator light is blinking green.

If the GSA indicator lights are blinking I would double check power to the J3051 plug pins 5 & 7.
I assume the A/P will light up on the GMC even if the system won't arm so it sounds like a lack of power.
Notice I said assume. If the system won't arm due to another issue it may be possible that the A/P light won't light.
Have you configured the ADAHRS?
The system needs a valid heading and pitch.

I have power to the 5&7 pins on the J3051 plug. I have configured the GSU 25 (AHRS) to tubes up, plugs aft (which is my orientation). I've done the interference calibration. When I do the Pitch and roll Calibration I get an error message: Aircraft in motion. I've done the calibration with me outside of the plane and reaching in to initiate the calibration. The plane is absolutely not moving, but I still get the message: aircraft in motion. I have not done the directional calibration yet ( move the plane to North,East,West,South).

I think you just found the first place you need to start.
The system needs a valid heading and pitch.
I would get the ADAHRS configured first. Then pitch and roll offset. You may find after that that things work.
I cannot help you with the config failure of the ADAHRS unless it is that you have the wrong up and tube direction configured.
I would think G3Xpert will pipe up here soon and before I make a mess of it.

Thanks for the help Mark. Xperts in G3X mucho appreciated.

I believe you need the AHRS calibrated and pitch offset calibrated to engage the AP.

Mark and Dbro,

Both you guys are correct. I had configured the AHRS to "Tubes forward". It should have been configured "Tubes UP". When I got that correct the AP popped up live and kickin'. Everything's good now. Only have to calibrate the Magnetometer. That should not be a problem.

BTW, for people that might have this issue in the future. The GMC 305 does have an indicator light and it does not work if the AHRS is not configured correctly. When the AHRS is configured correctly and everything else is good, then when the AP button is pushed the indicator lights light up and the AP engages.

Again, Thx a bunch.