Another constant alarm question

[Tismo]

1995 mariner 175 , soon as the key is turned on the constant alarm sounds. I’ve disconnected the oil sensor and changed out both temp sensors with no changes. Is there a way to test the alarm module ? This motor is kicking my butt lol. Thanks for any advice in advance.

 

[RickM46]

Usually Merc has 3 sensors - - low oil tank, over rev, over heat.