Engine Shutdown Woes

[wstockho]

I have a 2005 Hunter 33 with a Yanmar 2GM20(F) engine. Recently, shutting down the engine from the cockpit doesn't work. I checked the wiring behind the cockpit instrument panel and everything looks OK. I observed the solenoid on the back of the engine when the red shutdown button is pushed and it isn't moving indicating either a problem with the red push button, the wiring or the solenoid. I checked the voltage at the solenoid when pushing the button and saw a short spike to just over a volt followed by about 0.2 VDC. This leads me to suspect the solenoid, but I still have to check the voltage with the solenoid disconnected to eliminate the push button and wiring as possible problems. My problem is, if the solenoid is indeed bad, where can I get a replacement? I can't find any parts catalog on line that lists this item. I see similar solenoids that may work, but I can't find anything about the OEM solenoid that is currently installed. It is not in the owners manual I have. I'm also not completely sure that I'm on the right track with this, but, based on a review of the forums, this problem has affected others in the past. My understanding is that the push button is usually the culprit, but mine button causes a weak buzzer sound when pushed as it always did leading me to suspect that it is OK. My main issue is finding a good source of parts once I identify the faulty component. Any help would be appreciated.

 

[kloudie1]

Could be a bad pushbutton or wire or connections too. I would expect 12V at the solenoid when you push the button. Normally a solenoid coil fails open which would show as 12 V when you push the kill button. A bad connection (or wire or kill switch) on the other hand might not pass enough current to energise the solenoid . This would show as no or low volts at the solenoid (hot) connection.

 

[Bill Roosa]

You are on the right track. probe across both solenoid terminals as the first mate presses the button. Should see almost 12 volts. Disconnect the terminals if that does not check out and measure the resistance across the terminals. Should be < 1 ohm. also test across each terminal and the case. Should be very high resistance.
There is a high amp relay on the circuit. just like the starter solenoid. It is a small plastic box about an inch square. it is a module and can be pulled. Short across the power terms to see if the solenoid is working. i'm thinking that all the solenoids would be very similar in force and stroke since the injectors are all pretty much the same in construction in this aspect (ie the fuel control lever)
The solenoid for my boat is: 1502-12A7U1B, 12 volt, 30 amp, and supplies 9kg (19.84lb) of force I have that it is a Woodward solenoid but don't know how accurate that is. I did find one online but don't have the link.
Good luck

 

[wstockho]

Thanks for the quick reply. I now have some new things to check.