alarm sounds on Mercury 90 hp, 1990 outboard

[gratefulslim]

An alarm sounds constantly on my 90 hp 1990 Mecury outboard. There is plenty of oil in the reservoir. Is the sensor bad? Does this engine have other alarms than the oil level?

 

[ODDD1]

Re: alarm sounds on Mercury 90 hp, 1990 outboard

Slim...you will get a beep, beep beep from the horn if the tank is low on oil.....if the engine is too hot you get a steady tone..have seen alot of oil control boxes fail on these motors causing the horn to fire continuosly

 

[gratefulslim]

Re: alarm sounds on Mercury 90 hp, 1990 outboard

Thank you for your response. The horn is firing continuously. What would cause the engine to run too hot? How do I know if the oil control box has failed?

 

[Kevin20M]

Re: alarm sounds on Mercury 90 hp, 1990 outboard

Hello, I had the same problem with mine, try this, at the very front of the oil reservoir on the bottom, (it's not easy to see) trace one of the two blue wires towards the back of the engine, there should be two butt connectors, disconnect one of those and see if that turns off the alarm, I talked to a mercury service man, and he says that is a common problem, the sensor is only like 11 or 12 bucks, but I just run mine without a sensor, doesnt effect anything else, but I just have to remember to check my oil before each use, hope this helps, bye