Join Date: Sep 2006
Location: Yeocomico River, VA
Thanked 18 Times in 15 Posts
Rep Power: 10
Try to isolate where the circuit went open. Test resistance on the shaft (2 probes on the shaft). Should be zero. Put one probe on the coupling. Should still be zero. Keep moving away from the shaft toward the block and see where the circuit goes open. May sound obvious, but make sure you're testing clean areas - no paint, grease, dirt, etc.
It's possible that the 4 coupling bolts are so dirty or corroded that there isn't a good electrical connection (I don't mean to impugn your engine housekeeping, but your hull number indicates an older S28 - I had #521). It's quite possible that you aren't making good connectivity. As an aside with the Sabres bonding each through hull to ground, once in the water, you should have a zero reading.
Since the boat is out of the water, is it possible that it's just weathering? Regardless, I'd work on that infinity reading for now. Good luck.
Sabre 38 "Victoria"