When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It's common on these for the VSS to go bad. Its digital and controlled by a sensor. If anything, take it out, and tighten the 4 brass screws behind the Speedo. If that doesn't work, try a new VSS