Engine Alarm goes off before starting STB engine, and check engine alarm shows

[Setimos]

recently changed out manifolds, risers, and oil coolers on both engines. Everything fine, until today ran the boat for about 30 minutes. Anchored for 3 hours and when i went to start Stb engine the alarm (check engine) when on even before i started the engine. I did start the engine and the alarm continued, the oil pressure was fine, water pressure fine and temps were fine as the engine just started up. but the alarm was not going off. Shut everything down, turned of batteries etc... and tried again same result the Alarm, it is a high pitched alarm (not beeping) any ideas thank you Steve

 

[R-and-R]

There’s lots of good technical help available here, but you have to help them to help you.

Boat year and model ?
Engine description ?
Drive description ?

 

[scoflaw]

Low drive fluid?

 

[Setimos]

Fixed the problem since the risers and manifolds were just done in June, and all of the fluid levels are in OK range, i pulled the temp sensor on the manifold and the alarm shut off. I pulled the sensor and found that it was a plastic replacement the old ones were brass, I ordered a new one but had the old ones from the manifolds and tried that one and low and behold it worked. Keeping the new replacement as a spare. PS. be very careful taking out the old one if plastic they can easily break off. We are back in business. Sorry i have a 2004 34 Sundancer 8.1S 535 hours