I have a 2015 Nitro Z7 with a 175 Mercury Pro XS that I loaned to my cousin for a few weeks. When he brought the boat back, a little abused I might add, the speedometer did not work. I know a speedometer is not a big issue but I am one of those guys " if it's on there I want it to work no matter what it is". Can someone advise me on a little trouble shooting here, please? Does the Mercury have a sensor hole for the speedo?