My weather vane is now better than new
After it got repaired, I was able to get the sensor working in software. Everything worked, but there was one thing odd about the sensor.
To give some background, the sensor can tell the direction of the wind by triggering one of 8 magnetic reed switches each connected to a resistor. If I measure the resistance of the sensor, I can tell which direction the wind is blowing.
The east resistor measured infinite ohms. In hindsight this is obviously a problem, but I thought that everything was normal until after I did my repair. Why would there be a reed switch that connects to an infinite resistor? This is the same as having a switch connected to nothing.
I took apart the sensor once again to look for any damage. I was only hoping that I wouldn't have a busted reed switch. After some continuity testing, I found this on the east sensor:
This must be something that has been broken for over 6 years now. I was able to make the repair, luckily it was pretty simple. Just a jumper from the resistor to the reed switch.
I can't describe just how happy I am about this.
If the wind points between two of the sensors, then it will no longer think the wind has spontaneously pointed east.