I am 85 YO man and have a Triton 2005 TR-186 with a Mercury 150 HP 2 stroke XR6 engine. When I got the used boat, all good. Then the alarm would start beeping after running the boat for a few minutes. I have replaced the water pump and the 2 thermostats. Now though when I turn the key on before I start the boat, the alarm starts sounding. The local boat repair shop told me to check the 2 sensors on each side of the engine. How do I check a sensor? I hate to totally disable the alarm in case there should really be something wrong that would cause more problems and more expense.