over heat alarm ('99 vx225tlry)

[shoemake]

Problems with over heat alarm going off only when motor is in the lake. It will not go off while i have water hose hooked up. Its really odd. Sometimes it goes off as soon as i turn on the ignition (cool motor) and sometimes it takes it a while to warm up (idle speed). Sometimes the alarm will come on and go right back off within a few seconds and then sometimes it will come on and not go back off within 5 minutes or so. As soon as the alarm goes off, it will let me operate it normally and it does fine.
Several things i have tried:
*changed out pump impellar
*took out both thermostats, cleaned with lemon juice and put in pot of hot water and checked for operation
*ohmed out the little thermal couplings??? on top of the thermostats by heating with hair dryer

ANY OTHER SUGGESTIONS???

[jason8251]

Could it be one of the oil warning sensors. I know you said "overheat" but many seem to combine the two when talking about them and they use tha same buzzer and some of the same wiring.
Anyway I have a Seloc manual that shows the specs for both oil level sensors so you can read them out with a meter. I just had to mess with mine so its fresh in my head.

[shoemake]

guess it could be. but i have two seperate lights on my dash. one for over heat and the other for low oil. the over heat light is the one coming on.