Ok... kind of following this but i dont have a display so im just reading whats posted.
So you move black probe and you get a reading?.. the red/black wire on pin 3 is not connected or is at 19v ... theres no voltage potential here, so its either the same voltage or youve lost ground here.
Your meter will only read the difference between 2 voltages, so if you have ground ( 0V) and a volatge of 5V it will read 5V on the meter. If you have 5V and 2V on the other lead it will read 3V.
Sounds to me that rfed/black wire also has 19V across it.. or the same voltage as blue
