I have a 1989 300 Weekender. The shower drains into the well under the step as you step down into the cabin. I am trying to find the fuse that powers the manual switch for the pump. The switch is located on the side of the bathroom sink cabinet. I do have power to the automatic float switch...
does the new sync guage have an adjustment screw on the back? May be covered by a sticker. If so, you may need to get up to your cruising speed, getting your individual tachs reading the same. At that point, have someone adjust your sync guage to the center mark.