ST60 Wind Instrument

[rich ciolino]

My ST60 wind instrument quit working with no warning. The display dial is vertical at 12:00 and the digital display is blank (a dash in each digit). Mechanically the cups are spinning and the direction paddle is moving with the wind. Here's the voltages measured in the junction box inside the boat with the wires connected:
Red-Shield 7.97 vdc
Yel-Shield 7.97 vdc
Grn-Shield few milli-volts
Blu-Shield fiew milli-volts

With the Blu, Yel, and Grn wires disconnected (going to instrument display) this is what I measured on the mast side of the terminal strip in the junction box:
Red-Shield 7.97 vdc
Other three wires showed a slowly rising voltage from 250 milli-volts to about 1 vdc.

I'd like to determine where the source of the problem is, preferably without climbing up the mast to retrieve or inspect the anemometer assembly. Any instructions on what to do would be greatly appreciated.