Electrical Problems

[skids2212]

I went to try and help a family friends tonight to help figure out a problem with there 2005 Rxp cause they told me that it was not turning over so i instantly thought the battery was dead but i get there and check the battery with my DMM and there was 13.56VDC and the boat has power(dash has power and boats buzzer is just as loud as usual) but press the starter button and all u hear is the click from the relay...so i was just wondering if anyone has a wiring diagram and or has ran into this problem