Originally Posted by Thrall
He was probably trying to prevent the MMDC from getting fried if it leaked like wheelerd explained.
Personally I don't like things that don't "work" so 2 dead speedos in the dash would be annoying to me. I'd plug the lines in and give it a shot.
*2. Depending on which MMDC you have, look on ebay if you still encounter problems. If you have water pressure to the unit when underway, check that speedos are plugged in also.Have Fun.