The gauge for my Detwiller jackplate is not functioning. Is there a way to tell if it is the gauge itself or the sending unit?Can anyone recommend a good starting point for an 06 Cougar FTD w/225 ProXS, 26P 4 blade trophy? 2.5″ below pad?? I recently purchased the boat and without the gauge funtioning properly on the jackplate it is tough. Would just like to find a good point to start with.Thanks