Well, I’ve solved the first part of the puzzle. I took the sensor off and double checked the connections. It worked flawlessly when I would tilt it manually. However, the angle of tilt when mounted on the garage door was not as severe, so the ‘open’ condition caused a bit of ‘sloshing’ of the mercury and must have confused the sensor electronics. I remounted the sensor with about 8 degrees more angle and it now works flawlessly.
Also, the only piece of information I had regarding the external connector was that it should be connected with a normally closed contact per the installation instructions that came with the sensors. I’ve learned that the internal reed switch and the external switch function as an .OR. gate between them. Thus, if either the internal or external switch is open, the sensor reports open. To disable the internal reed switch to be closed all the time required permanently mounting the magnet next to the sensor. This allows the external connector with the attached mercury switch to provide the only open/closed input. I would guess that one of the jumpers on the logic board can be set to disable the internal switch but I could find no documentation to support it. The permanently affixed magnet is not attractive but is a simple solution.
Now, if I could just find a smart app to allow me to get text messages when the door is left open at night, I’ll be done. I read that there is an app called ‘Is My Home Secure’ that provides the functionality but the code has been taken down. I’d like to find an app that sends me a text message if my door is open during the evening or between a set time. I’m ok with the door being open during daylight hours.
PS The GoControl bundle of two window sensors and one motion detector allowed me to create two tilt sensors for $50 total. From what I read about the other dedicated garage door tilt sensors, they seem a bit unreliable and fairly expensive. The GoControl package is a pretty good deal.