I have a 2002 triton with an 02 150 mercury on it and after the motor is started the low oil / over heat alarm will sound every time I trim the motor up or down. Then after I get on plain it will start again. It comes and goes and is not continuous. I do not have the owners manual for the motor.

Any help will be greatly appreciated.

Thanks.

Had a similar issue this Spring with my Mariner 150 EFI.

First, what cadence is the alarm? Steady beep? Beep beep beep?

The type of cadence will tell you which type of alarm it is (either overheat or oil).

I believe a steady beep is overheat. The other is oil system.

My alarm was beep beep beep style and long story short, the Oil Warning Module on my motor was bad. Having it replaced solved the issue.

If yours is an oil alarm it could be coming from a couple places/problems and I'm no expert so I'l refrain from fix it advice.

If it is an overheat alarm, you should be able to see your temp guage go up and stay up. Is your motor spraying water?

Do an online search of "Mercury 150 alarm". That will yield you some possible causes or solutions.

I have an 02 Opti and have had 2 alarm issues.  The first one was the constant alarm and the motor overheated while I was idling along eating lunch.  A new powerhead gasket took care of that.

The next one was the intermitten oil alarm.  The motor wasn't overheating so I assumed it was getting oil.  I took it to a shop and it turned out to be the float and sensor in the oil tank.  A new tank and new sensor took care of that issue.

It's not constant and it comes and goes while I'm going. The only thing that is throwing me off is that it does it every time I trim the motor up or down.

It's probably time to take it in before some major damage is caused.