Seawater pressure alarm
 

Anybody have a cheap way of a low/ no seawater pressure warning system?

find a normally open pressure switch and wire it to a light or buzzer maybe?

excellent, thank you

Why these aren't installed on every merc from the factory is beyond me...

Since you bring up the question. I am in the process of developing a product that can monitor all pressure systems with adjustable sensors and rpm triggered alarming. Sounds like exactly what you are looking for. The problem with water pressure is that it is near zero at idle so a normal switch would alarm all the time at idle. My system should be on the market in about 30 days. Target retail will be around $300.

Bob Lloyd
Full Throttle Marine

They are on Smartcraft engines. The pressure transducer is located on the outlet of the seawater pump.

That one says it's set for low flow engines, and alarms below 1.5 gpm. Too low an alarm point to be useful for a typical marine V8?