Does anyone have a copy of the wiring diagram or the maintenance manual for a Century 21 auto pilot? I had a dual Garmin G5 system installed and there is a wiring issue between the new G5 HSI the GAD 28B and the auto pilot. Current thought is the problem is at the auto pilot.
I don't have one but see that you can buy one ($300) from
. You might try Autopilots Central in Oklahoma or Executive Autopilots in Sacramento.
I'm surprised your avionics shop doesn't have the manual.