The buzzer alarm on my Universal Westerbeke M3-20B is going off when it is not supposed to.
Normally, when I turn the key the alarm buzzer goes until I depress the preheat, at which point the preheat solenoid clicks, the fuel lift pump works, and the buzzer turns off. I then press the starter button as well, the engine starts and I let go of both buttons. The buzzer *should* come on momentarily until the oil pressure reaches 15psi (or is it 5psi?), and then the turns off again. The engine then continues to run normally at a fast idle until it is warmed up (cold engine stalls on a slow idle).
Everything appears to be the same now, except that the buzzer keeps going after engine start, constant and not pulsating.
The troubleshooting page suggests three things
1. Resistor shorting.
2. Fuel pump.
3. Oil pressure switch.
and offers diagnoses
1. Check resistor 1000 ohm. resistor found between preheat solenoid "I" terminal and ground.
2. Fuel pump coils shorting.
3. Oil pressure switch internal contacts not closing properly.
I don't know which of these is more likely, but I replaced the preheat solenoid only a week ago, after the old one broke it's mounting bracket and shorted out (due to my own clumsy inspection) on the block. The engine worked normally for one outing after that.
This blog post has a nice picture of the preheat solenoid
Replacing the glow plug solenoid
This page has all the technical manuals for my engine
I *think* I tested (1), above, and found there was not 1000ohms of resistance between the new preheat solenoid "I" terminal and ground (will check again), but I don't actually know where that resistor lives.
I see the 1k ohm resistor in the wiring schematic and diagrams, but not in the parts manual. What does it look like and where can I get a new one?
Comments and suggestions welcome.