Stop solenoid not working TMD40

[Leighb]

The stop solenoid on our port engine stopped functioning while we were away on holiday so had to stop it manually, no big deal but it means lifting a floorboard in the wheelhouse.

It had been intermittent earlier in the year, but the engineer said it was "sticky" and he had sorted it.

I am unsure if the problem is with the solenoid itself or with the wiring or the switch.

I connected my multimeter with Pos to the terminal on the solenoid and Neg to the engine . Then with engine switch ON tried pressing the Stop button, expecting to see a voltage on the meter, but not a flicker.
Does this mean there is no supply to the solenoid, or have I got my connections all wrong? I wondered if perhaps it could only be energised when the engine was running? Looking at the wiring diagram it appears not to be the case.

Can anyone enlighten me please?

If the solenoid needs to be removed, is that straightforward? The parts diagram seems to show a spring beneath it, and I am concerned that something might leap out and be difficult/impossible to refit correctly.

 

[Montemar]

I occasionally get this with the port TAMD41B. I can go below to the lower helm, put the key in and stop it from there.
This suggests my problem is a dirty contact in the bridge ignition switch. It sometimes works if I repeatedly and slowly go to the stop engine setting.
Get someone to operate the off switch when the engine is not running. You should be able to hear the solenoid on the engine click.

 

[Leighb]

Thanks, on mine the Stop button is separate so not part of the ignition switch, but bad contacts could still be the problem.

I can operate the button at the helm with the engine directly under my feet! I certainly cannot hear any click, but that still could be electrical or mechanical fault?

 

[GrahamHR]

I understand why the stop solenoid is there on diesels..................but why do marine diesels still need to have an additional stop position on the "ignition" switch ? For probably hundreds of millions of Diesel cars stopping their engines by putting the "ignition" switch ot off/ 0 has been the norm for years. They may well have stop solenoids as well. but car manufacturers seem to have been more able to be sensible in that respect than their marine counterparts.

 

[Montemar]

Thanks, on mine the Stop button is separate so not part of the ignition switch, but bad contacts could still be the problem.

I can operate the button at the helm with the engine directly under my feet! I certainly cannot hear any click, but that still could be electrical or mechanical fault?

It isn't very loud! It possibly takes two people, one to do and one to listen.

 

[VicS]

The stop solenoid on our port engine stopped functioning while we were away on holiday so had to stop it manually, no big deal but it means lifting a floorboard in the wheelhouse.

It had been intermittent earlier in the year, but the engineer said it was "sticky" and he had sorted it.

I am unsure if the problem is with the solenoid itself or with the wiring or the switch.

I connected my multimeter with Pos to the terminal on the solenoid and Neg to the engine . Then with engine switch ON tried pressing the Stop button, expecting to see a voltage on the meter, but not a flicker.
Does this mean there is no supply to the solenoid, or have I got my connections all wrong? I wondered if perhaps it could only be energised when the engine was running? Looking at the wiring diagram it appears not to be the case.

Can anyone enlighten me please?

If the solenoid needs to be removed, is that straightforward? The parts diagram seems to show a spring beneath it, and I am concerned that something might leap out and be difficult/impossible to refit correctly.

This was sensible thing to try .... it indicates a defective stop button or, more probably, a bad connection somewhere in the wiring.

Another thing you could try is a connection directly between the solenoid and battery positive. Provided the isolator is closed that can be the main battery connection on the starter solenoid. If the engine is not running I'd expect to hear a click if the stop solenoid is working. Finally repeat this with the engine running and it should stop it if the solenoid is OK.

 

[volvopaul]

I understand why the stop solenoid is there on diesels..................but why do marine diesels still need to have an additional stop position on the "ignition" switch ? For probably hundreds of millions of Diesel cars stopping their engines by putting the "ignition" switch ot off/ 0 has been the norm for years. They may well have stop solenoids as well. but car manufacturers seem to have been more able to be sensible in that respect than their marine counterparts.

A
Answer, all road vehicles have energise to run system so for example if your battery went flat your engine would eventually stop.
Your engine is energise to stop so no voltage is required for it to run which is a blessing when your out at sea with flat batteries.

 

[dragoon]

I understand why the stop solenoid is there on diesels..................but why do marine diesels still need to have an additional stop position on the "ignition" switch ? For probably hundreds of millions of Diesel cars stopping their engines by putting the "ignition" switch ot off/ 0 has been the norm for years. They may well have stop solenoids as well. but car manufacturers seem to have been more able to be sensible in that respect than their marine counterparts.

I think it has to do with marine "keep it simple" mentality. Most cars have an ETR (energised to run) solenoid, which needs energising to pass fuel - this is good for anti-theft of course. On a boat, it's designed the other way around (ETS - energised to stop) - run, until stopped when energised. Consequently, unless you introduce some logic (electronics - which are another potential source of failure), switching to a dedicated stop position or pushing a contact switch is required. Or on earlier marine diesels, you need to pull a stop lever.

 

[Leighb]

Thanks for the further helpful replies. I have a clearer idea of how to proceed. The first thing I will do, which I did not have time for the other day, is to repeat the multimeter test on the starboard engine with a working stop solenoid. I will then try Vics suggestion with a direct cable to check if the solenoid itself is OK.
If so then it is track down the bad connection.

 

[GrahamHR]

Volvopaul/ dragoon, thanks for the explanations re marine diesel stop philosophy. I'm still not 100% understanding it regarding it being a safety feature if the battery is dead ( they don't do that with big twin petrol engined seagoing boats in the US).

A modern common rail diesel like a D4/ D6 requires electrical power to operate the injector solenoids ( isn't it something like 80V under that black painted aluminium cover, if I remember what the warning label indicates). Without power to the injector solenoids ( flat batteries. broken alternator) , won't they simply not operate ? Why would the engine then carry on running ( unless they "fail safe" to permanently open). ? Or am I mistaken in thinking the D4/D6 are common rail injection ?

 

[dragoon]

Volvopaul/ dragoon, thanks for the explanations re marine diesel stop philosophy. I'm still not 100% understanding it regarding it being a safety feature if the battery is dead ( they don't do that with big twin petrol engined seagoing boats in the US).

A modern common rail diesel like a D4/ D6 requires electrical power to operate the injector solenoids ( isn't it something like 80V under that black painted aluminium cover, if I remember what the warning label indicates). Without power to the injector solenoids ( flat batteries. broken alternator) , won't they simply not operate ? Why would the engine then carry on running ( unless they "fail safe" to permanently open). ? Or am I mistaken in thinking the D4/D6 are common rail injection ?

Well you're talking about modern technology for me. But, yes, modern common rail engines rely on electricity much more than the older engines that I'm used to. Once running a lot of 'true marine engines' don't require any supply once they're started - the alternators can fail and the battery bay can flood - they will keep going with just fuel and air.

That said, if an ETR solenoid fails in use, the engine stops and you break down. If an ETS solenoid fails, nothing happens at sea, but you can't switch the engine off in port. The latter is generally preferred - at least in my book

 

[Leighb]

Another thing you could try is a connection directly between the solenoid and battery positive. Provided the isolator is closed that can be the main battery connection on the starter solenoid. If the engine is not running I'd expect to hear a click if the stop solenoid is working. Finally repeat this with the engine running and it should stop it if the solenoid is OK.

Many thanks. I did this today, first of all repeating the test on the STB engine which correctly showed 12V when Stop button pressed. The Port solenoid clicked when wired directly and stopped the engine as it should.
I then investigated the other end at the panel. I was able to show that the Stop button operates OK. There has to be a break in the wire between the Stop switch and the solenoid. As this is all inside original cable loom of considerable length I think that it is beyond my abilities to find the break.
I am thinking that the easiest way would be to run a new cable from the output of the Stop switch to the solenoid.
Is there anything fundamentally wrong with that idea?
Thanks again for all the helpful advice.

 

[dragoon]

Many thanks. I did this today, first of all repeating the test on the STB engine which correctly showed 12V when Stop button pressed. The Port solenoid clicked when wired directly and stopped the engine as it should.
I then investigated the other end at the panel. I was able to show that the Stop button operates OK. There has to be a break in the wire between the Stop switch and the solenoid. As this is all inside original cable loom of considerable length I think that it is beyond my abilities to find the break.
I am thinking that the easiest way would be to run a new cable from the output of the Stop switch to the solenoid.
Is there anything fundamentally wrong with that idea?
Thanks again for all the helpful advice.

Is there continuity (a circuit - testable as ohms resistance with a multimeter) from the switch to the solenoid? If there is, it's possible the switch is no longer able to pass the current required to operate the solenoid. You could also verify by putting a wire across the switch terminals to see if it operates the solenoid, whilst the switch itself fails to.

If there is a break, those Volvo looms do have multiplugs between the dash and the engine. They are enclosed in a rubber shroud/boot, but you may want to start there - I recall on mine they are in the engine room, not far from engines - maybe water has got in?

Otherwise, I see no problem in running a wire, although it is of course a 'modification' from the original circuit.

If I recall, you have a Storebro. Do you have the original wiring diagram (mine has it in an A4 Storebro marked ring folder)? You might be able to see if there is a relay in the stop circuit. From memory, I can't recall one, but it could be worth checking.

 

[Leighb]

Is there continuity (a circuit - testable as ohms resistance with a multimeter) from the switch to the solenoid? If there is, it's possible the switch is no longer able to pass the current required to operate the solenoid. You could also verify by putting a wire across the switch terminals to see if it operates the solenoid, whilst the switch itself fails to.

I hadn't tested that, assumed that if no voltage at the solenoid then there was a break in the wire.

If there is a break, those Volvo looms do have multiplugs between the dash and the engine. They are enclosed in a rubber shroud/boot, but you may want to start there - I recall on mine they are in the engine room, not far from engines - maybe water has got in?

There are at least 2 multiplugs, one in the dash panel and one in the engine bay, neither in an area likely to be wet though. I have not tried to open them up, not sure how easy it is?

Otherwise, I see no problem in running a wire, although it is of course a 'modification' from the original circuit.

If I recall, you have a Storebro. Do you have the original wiring diagram (mine has it in an A4 Storebro marked ring folder)? You might be able to see if there is a relay in the stop circuit. From memory, I can't recall one, but it could be worth checking.

Yes I do have the Storebro manual with circuit diagrams, as far as I can see there is no relay in that circuit, just for the glow plugs and starter.

 

[dragoon]

You can have a situation where (with the load disconnected - i.e. the solenoid), you get circuit voltage at the terminals. But when you connect the load, it fades away to nothing. This is due to high resistance in the circuit (effectively, the voltage drops over the high resistance as per ohms law). Just to eliminate this scenario bing caused by a failing switch, it's worth bypassing the switch.

With the multiplugs, I recall you pull the rubber boot back to access the plug. I think (from memory) they then just pull apart, but there may be something you need to depress to free them. If the dash one looks dry, I would start with the one in the engine room - there's more scope for damp.

Do your engines have the box on the top front of the engine, containing the relays? I recall the cabling should route through there - worth looking inside in case someone has added additonal connectors in the past - perhaps when removing the pump for repair. I recall I have a couple of terminal blocks in mine.

On mine I think the cable route for this circuit is from behind the alternator, between the heat ex and the block, through the relay box, and onto the solenoid. Check for chafing or additional joins in this area. I did replace some chafed cable for the temp senders in this area once.

 

[Leighb]

An update.
Having established that a) the solenoid worked, and b) The switch worked, I decided to run a new wire direct between them.
This has now been done, tested and working.
The most difficult bit was undoing the fiddly nut on the solenoid terminal and then refitting. Access was very tricky as it was directly under the fuel return line, and one the engine side by the odd plastic cover which I enquired about in another three.
It is one of those, to my mind, stupid "nuts" that are round, with no flats and a slot across the top which a screwdriver cannot engage because the top of the thread protrudes through!! aaaagh!!!

I eventually managed to get it off with a narrow jawed locking "mole" grip. When trying to replace it, it fell in the bilge! Fortunately I have a large supply of odd nuts and bolts and found a proper nut that fitted and could be done up with an 8mm spanner.

Running the wire though and fitting new terminals was the easiest bit.

Anyway job done and we can again stop both engines without having to lift a floorboard and use the manual stop lever.
Thanks again for all your advice, these fora are such a huge asset due entirely to the helpful folk who are willing to offer the benefit of their experience.