Wire colors in cable, red, blue, green, yellow, white, black. What's what?
Open it up and those wires go to a small PC board that has, red, red, black, black, green, white. What's what?
Look at wiring schematic. Hint: "potentiometer wiring is 28 ga. Wind speed coil wiring is 22ga"
Sure enough, two reds are different wire gauges and two blacks are as well. The thicker red and black wires are for wind speed and the thinner red and black are for wind direction. Then it was just a matter of using an ohm meter to verify which wire on the board is which wire in the cable.
Need to get a stub of 1" pipe and a floor flange. Screw the flange down to a piece of wood and put pipe into the flange. Then the wind monitor can mount onto the pipe. Basically, I'll be making a stand for it.
I'll make some lines on the board to represent points or directions on a compass for N, S, E, W. Then I can put some DC voltage to the potentiometer and find out where North is by turning the weather vane part of it and reading voltage between negative DC and a third wire. The lowest reading, at or near zero volts is North and 180 out from that should give me the highest voltage reading.
I can take it to work the weekend after next and do some testing for wind speed readings.
Then I just need a $400 controller to connect it to so I can see the wind speed/direction on screen in real time.(with it mounted it outdoors of course) I'll probably put it up near the house for now on a pipe that will really be too short.
The installation part of the manual has guidelines for the effects of buildings on wind. The wind gets disturbed for twice the height of a structure, above said structure and upwind from it. The tunnel is 15 foot tall so I'm going to put the wind monitor 30 feet away from the tunnel, in the direction of the prevailing winds.(and storm gusts) I'll probably put it 15 foot off the ground which is pretty low but I'm not looking to record proper weather data. I'm using it to close up a 15 foot tall high tunnel in high winds.
Looks like it will be decent weather to set a tunnel frame tomorrow.
0v = 0 or 360 degrees | 1.25v = 90 degrees | 2.50 = 180 degrees | 3.75v = 270
Due North 
Nearly due North 
Nearly due West (West = 3.75 vdc) 
Nearly due East (East = 1.25 vdc) 
Could have moved it slightly to get exactly 1.25 VDC for East - 3.75 for West etc but I was just verifying it reads smooth in the full 360 degree circle which it does.
The controller will convert the voltage to degrees as follows;
0.00 vdc = 0 degrees (N)
1.25 vdc = 90 degrees (E)
2.50 vdc = 180 degrees (S)
3.75 vdc = 270 degrees (W)
and so on
I'm going to have to learn degrees as on a compass. Would be easier if my house faced North but it faces S/SE.
Note to self; 315 = cold wind coming down the road(NW) - 180-270 = predominate winds(S-W)