2002 Yamaha F115 has audible and wont start.

[Capt.'s Shocker]

This weekend started my motor and it ran for about 10-15 minutes and than shut off. Tried restarting it and it cranks but alarm is going off and wont start. Alarm is not present when i turn it on but happens when I try to start. i have checked the thermostat and have already replaced impeller and thermostat. there are only 2 reasons for alarm. Temp and low oil pressure. I have had the temp issues before and the motor would run just at idle or a little higher. So I'm thinking oil pressure. I have been researching and could be oil pressure switch, wire harness and I'm hoping not but could be the oil pump. anyone have this problem?