[pjdion]

I have a 2002 Tiara 3800 with 517 hours.  Yesterday, when I got to the boat one of the first things I do when I get on the boat is open the window vent.  Didn't open.  Blower didn't turn on. Windshield wipers didn't turn on. Hmmm. Then I turned on the key to the port engine....nothing.  Once I pushed in the battery parallel the port engine started.  However, as soon as I took my thumb off the battery parallel the engine stopped.  I did notice that all the items I mentioned earlier worked with the engine on (while my thumb was on the battery parallel).  I even turned on both engines (with thumb on battery parallel) and as soon as I took my thumb off the battery parallel the engines turned off.  I checked all the engine batteries and all registered 13.59 volts, but this was with the battery charger on.  As I did all of this I was on shore power. Any advice?