What year is your motor? Thermostats can go bad, and will, doesnt matter if its brand new or 5 years old..Just my two cents for what its worth. You could even remove the stat and see if she still sounds the alarm. Or you could look into checking the voltage input and outputs of your sensors. If you have a service manual, it might give you these specifications.
But again, dont go guessing parts like they have stated earlier, you can cost yourself more in the end..