The black wire on the M terminal can lead to some suspicion unless you actually have a master valve or pump installed.
I would start with an Ohm meter since I suspect a short or miss wiring.
- Turn on your Multi meter to the lowest Ohm setting which is usually 200 ohms.
- Place the black lead to the C terminal.
- Place the red lead to terminal 1 for about 8 seconds, then 2,3 and so on.
- On those Richdale valves, the Ohm reading should be from 20 to 27 ohms.
- A lower reading indicates a cross wiring with other valves.
- In the event that most of the readings are too low, I would consider changing the sprinkler cable to the valve box while taking note as to which color goes to each valve and assign them a terminal on the controller.
I have a standard practice to test each station prior to changing any controller over to a new one. That helps to eliminate the frustration and rule out if the new controller has a malfunction or if the system was bad to begin with.