Water Leak UPDATE - FIXED

Good morning fellow campers. I've developed a water leak somewhere in my system and am baffled. We normally carry about 1/4 tank of fresh water in our coach when traveling. Two weeks ago I noticed a large puddle of water under the coach and found that the fresh water tank had filled overnight and was leaking out the overflow. There is a gate valve in the electric bay that is opened to fill the FW tank and I assumed it had failed causing the problem. I cut the incoming line and put in a separate valve just behind the original one using a Shark Bite valve. Removing the old valve was not an option due to it's placement by Monaco. Anyway, that did not correct the problem. So, I removed the new valve, left the water line disconnected and turned the water back on. No water..it appeared the old valve was working just fine. I left it that way most of the day and had no leak. Put the new valve back in the line, buttoned everything up and went on my way. Today I woke up and have another puddle. A check of the FW tank shows it's full and overflowing. Both valves are OFF.

I can only assume there is another valve or a spur that runs to the FW tank ahead of the shut off valve but since all the water lines run thru the body there's no way for me to trace them back to the source. I've looked at the Manibloc system and see nothing of help there. Has anyone else had this problem? If so, what was the fix. I'm open to any and all suggestions. I've also posted this over at IRV2 to the Monaco group for help. TIA.....Dennis