Back to the specific conditions of the OP,
My windex died as a result of a collision with a heft wind blow chunk of tree on week three of my brand new Gemini. It points from 0 to 90 degrees, now where else - wind speed was not affected.
I still haven't fixed it because I hate going aloft.
It's important only in that I can't operate my St60+ in windvane mode, otherwise every time I've checked the boat still sails just the same.