Good luck on that. I had similar issues. The ST50 wind transducer was broken and unrepairable by anyone who had a clue. There is a replacement available in the UK for about $600 US two years ago. US Raymarine is basically disinterested in ST50 Autohelm issues. Anyhow, since my backlighting was going out, I bit the bullet and put in a new suite of instruments. The good news was the ST50 wind cabling and mount was OK with the ST60+ transducer. It did take a while to sort out the wind parameters tho. The bad news was I am still dealing with the depth issues. I decided to go ST60+ because I wanted to use my old transducers rather than pulling the boat and dealing with 5200 adhesive. Also, I did not want to pull an new backbone for NEMA 2000. IF I HAD, I would have gone with a Furuno instrument suite. This being two years later, you may want to consider the cascade effect of your choice and think non-Raymarine.
Geesh, I forgot the reason I replied to begin with <blush>. The interface of a ST60 wind transducer and ST50 head lacks windspeed as I recall; I'm pretty sure. However, lots of other people have had a problem syncing the two.