Wind transducer gone bad?

I replaced my wind transducer last year, including a new cable. It is connected to an iTC-5 and hence to the network. It all worked fine until last week.

Symptoms:
1. Wind speed most of the time shows just dashes. Sometimes a number but most of the time = dashes.
2. Wind direction shows straight up, or 122 degrees to port. Nothing else.

Measurements:
Red to shield = 2.89v, steady
Yellow to shield = 1.1v to 1.5v, variable
Blue to shield = 0.92v steady
Green to shield = 0.92 steady

If the red is disconnected at the base of the mast, red to shield (from iTC-5) is 7.98v.

Sounds like a short or other problem at the masthead? What is your recommendation for next steps?

Thanks.

Paul