Engine stop button

[furball]

The stop button stopped working Sunday. 2006 Yanmar 6LP
I tried jumping the two connections on the back side of the stop button but no joy.
The key does shut the motor down.
I assumed that the button was bad when the key shut the engine down but after jumping the two leads on the stop button and the engine kept running, I'm not sure what to check next.
Does the key and button activate the same solenoid?
Thanks,

John

[RobS]

Yes, there is only this one shutoff solenoid on the inj pump and the one relay connected to it. The relay is above the bell housing on the intake side of the turbo but none of that is your issue.

If the key works and the button does not it sounds like its the wiring to the button from the key switch so I would start by tracing those and see what you find. You can double check the switch with a continuity meter..

[catalina_mike]

I tested mine upon purchase. It was the stop relay that activates the solenoid.

Let me add a bit more. The key enables 12 vdc to all the gauges and devices (relays, alarm, etc) on the motor and gauge panel. The start button engages (sends 12 vdc) to the starter. The stop button sends 12 vdc to the stop relay located on the transmission end of the engine. Looking aft it is left side of engine. The stop relay has NC (normally closed contacts) that allow power the the fuel cutoff solenoid by the fuel pump. Yanmar recommends not using the key to shut down the motor. The PO of mine did so for quite a bit.

[Tree]

I had quite the opposite this time last year. Running along happily doing 18 knots when the engine stopped without warning. The stop relay had corroded. 5 minutes job to replace and that includes trimming the cable ties.

[RobS]

Same here Tree. I happened to have just completed my shaft seal replacement, engine alignment and had prop checked and tuned so I was doing a WOT test and the relay shut the engine down while I was running full throttle. Talk about timing and 30 seconds of fear...I thought for sure I was going to open the engine box to an bilge full of oil, coolant and ugliness. What a relief.

Thinking back on it now, if I were a 6LP owner I would replace it for the $30. Fortunately, since I was doing a WPT test I was in an open & calm area, etc so the location was okay.. If I had been running in a ripping inlet or navigating a crowded waterway things coulda got ugly real fast. Here's some pics and info if anyone is interested..

[catalina_mike]

Great pictures of where it is. I traced my wiring to find it. I went with a universal relay used for fog lights 30A rating picked up at autozone.. No Yanmar dealer open on Saturday.

[Tree]

Certainly leaves you with the fear of staining in the pants department when it does it Rob! Thr location of it is prone to being a problem. I found mine had corroded simply because water had got on it from when the zinc above it had been replaced. It's now clipped up in place with their terminals on the underside to stop that happening again.

[catalina_mike]

Same story here.. http://photo.pacificwestcontrols.com/~M ... e/R8RYP85c

[furball]

Thanks for the photos and explanations.
Makes a lot more sense now and a heck of a lot easier to find.

John

[furball]

So I had "my guy" call Mack Boring today to order a replacement relay and I wanted to pass along the info we received.
According to MB, Yanmar engines, 6LP, are designed to turn off with the key and no Yanmar panels for that motor ship with a stop button. Albin add on apparently. He asked that I check the wiring diagram in my manual, LOL.
If the key turns off the engine then the relay is working and the button must be bad.
He called is a start relay, not a stop relay.
Guess that's why the stories of sudden engine shutdown but none regarding not stopping.
I'm going to check the stop switch when I go down this weekend and I'm ordering a spare relay regardless.
I'll let you know how it turns out.
Know I need to understand how a 4 prong relay works.

John

[RobS]

Seriously? I think the rep at MB is the one who needs to check the wiring diagram and check his source of information. All three Yanmar supplied panels have a Stop button (the B Panel, the C Panel and the D Panel....ALL of them) , section 4.7 on page 31 of the Yanmar supplied operation manual gives specific instruction on stopping the engine with the Stop button and, of course, the Stop button is shown in the wiring diagrams.

I agree that the relay is not specific to your issue, it was a sidebar to this thread..

[Tree]

When my relay started acting up I couldn't stop the engine with the stop button so I believe that relay does both functions. If I recall 5 of the six terminals are used on it. Are we absolutely sure that the relay we've spoken about doesn't do both functions?

[Paddy]

Mine is key off, confirmed when I had it surveyed by a very reputable surveyor. Stop button is there but does nothing. That was at 588 hours in 2013, now at 1175.

[catalina_mike]

My wiring diagram clearly shows the stop button. During the survey for my purchase the button was discovered to not work. They ordered a Yanmar factory stop button for my panel and I told them I would replace it and not to worry about it. I replaced it and it still did not stop it. That is when I traced the wiring and found the relay issue.

[Paddy]

So during my intermittent start problem, I replaced the relay, start solenoid, starter, both buttons, and ignition switch (which was the problem). During this 2 month headache, I pulled the factory dash many times. The yammer gauge cluster does have a wired stop button, but even with flipping the buttons out and all the replacements, it has never shut down the engine. With the key on, the starting solenoid is energized, with the key off, the shut down solenoid is not energized. If the key appears to be doing the job of the button, what is the possible consequences of not having a working STOP button? Just wondering, this is my first diesel.