Logo
FULL SITE MENU

Alarm buzzer

S

seaway11

New member
Mercruiser 7.4 MPI. I'd like to test the engine temp alarm buzzer circuit. The buzzer sounds when I turn the key on for about 2 seconds. The sender was recently replaced. There are 2 wires. a yellow and a black. I tried grounding each wire with the key on. I tried heating the sender with the wires plugged in, no buzzer. Any ideas? Thanks
 
on a late 90's 7.4 MPI engine, the sensor at the thermostat housing with yellow and black wires is the ECT sensor...

a lot depends on the specific ECU on the engine and the code programmed into it.

The engine does NOT come from the factory with the 'classic' stand alone warning horn system driven by switches in parallel.
 
Can you add on a high temp warning buzzer to a system that doesn’t have one? I have a 4.3 Mercruiser with an open system with the stock temp gage on the dash. I wouldn’t mind having a high temp warning back up. It’s pretty easy to miss a sudden temp change on the gage when fishing or crabbing. Kirk
 
absolutely...all you need is a 12 VDC buzzer, powered from the ignition switch. and a temperature switch (that closes at the desired temp)...As an example look up Sierra's MP41400 kit - it has the coolant overheat and a low oil pressure switch.
 
Back
Top