Here's the culprit! In a post on Monday I described how N631S's S-TEC System 50 autopilot failed en route from DC, giving me the opportunity of scrape the rust off of my technique for hand-flying an ILS approach in IMC.
Dave discovered that if he perturbed the wires at the pictured connector it would cause the autopilot to go off line. Everything else checked out fine, so he removed the connector and hard-wired the installation. No more connector to act as a potential point of failure. The system is now operating "ops normal."
I've developed a great deal of respect over the years for Dave's capabilities and his approach to his profession. One of his pet peeves is the use of connectors whose only purpose is to make the installation technician's job easier. For the sake of saving ten minutes under the panel, you accept a small degradation in system reliability. The possible consequence...is what happened to me on Monday.
Once again, the service from Three Wing has been exceptional. These guys are very good at what they do. N631S and I are 'good to go' for the trip south on Friday...and the weather is looking promising.