Westerbeke W52 stops suddenly and unexpectedly

[Nord Sal]

In the nine years that I've had my Westerbeke W52, it has run well. It has always started very easily and run smoothly at all speeds.

I brought my boat down to Washington state from Alaska last September. Due to the need to pass trough Canada expeditiously during the pandemic and that I experienced headwinds nearly every day, I motored the whole time, other than three days. The engine performed flawlessly during this time over roughly 1,000 miles.

I changed the oil and filters last fall, and then proceeded to tear apart my boat's interior repainting and refinishing which has kept me from leaving the dock. During this time, I'd run the engine for an hour or so every four to six weeks just to exercise it. Last week, I finally got my cabin back together (mostly), enough so that we left the dock for short trip and enjoy the more southerly latitude to go do some swimming.

Just a few minutes from the dock the engine suddenly lost power while motoring. When this occurred, I saw the instrument panel lights turn off, the gages lose power and the oil pressure/H2O temp alarm did not sound. Within a minute, the alarm sounded and the instrument panel lit up (key was left on). I then depressed the start button and the engine fired up immediately and ran smooth like normal. This only lasted a minute or two before the engine died again in the same manner. This happened maybe four or perhaps five times. Each time, the power came back after a minute or so (probably not long really, it just seemed long!) and then the engine ran fine. The last time the engine stayed running and we motored back to our slip.

There is a solenoid on the injection pump which stops fuel delivery when it is de-energized. It appears the circuit is being completely de-energized somehow and the solenoid closes shutting down the engine, just as if I had turned off the key.

The engine has a 20-amp circuit breaker which breaks the circuit in the event of excessive current. This was the first thing I checked and the breaker did not trip.

I can only surmise that there must be a faulty connection somewhere in the wiring harness and that the vibration of the running engine is causing it open and de-energize the solenoid, killing the engine. I suppose the key switch could be faulty though that seems like a very low probability.

The harness appears to be all original to my eyes. The only modification I can see are two ring connectors that I replaced on the starter solenoid that had somehow been damaged (some broken strands), perhaps when someone previously worked on the starter. I did this several years ago and used good-quality heat shrink crimp terminals (Ancor). I have not had a single issue with these and they look fine. I also have disconnected/reconnected some of the electrical connections (circuit breaker, glow plug solenoid, injection pump solenoid, oil pressure sensor and switch) when I removed the injection pump a few years ago because the seal had failed and was allowing diesel to enter the crankcase. The engine was running well before (other than 'making oil') this work and has run well for four years since. I mention this because it's the only things I know of where the electrical connections were touched.

The wiring diagram for the engine is illustrated on page 252 (page 54 of 78 of the linked PDF) of the parts manual. https://www.westerbeke.com/parts%20m...15.0_parts.pdf

I'm posting this to get suggestions what might be causing this and where to look.

Thanks in advance for any help!

[Lodesman]

I think you were on the right path with the 20A breaker - I'd look at the wiring between the alternator and it (via the start solenoid). Then between the 20A breaker and the panel. Guess based on power going out to panel, and everything downstream of that (fuel solenoid) being affected.

[Nord Sal]

Thanks for the reply LM.

Hopefully the wiring diagram shows in this post. It's difficult to follow the lines in the diagram where they cross and parallel, so I've highlighted the 'run' circuit (as best as I can tell) in a light yellow.

I've checked the connections that have reasonable access. They are all tight and don't show any corrosion or broken strands.

I've highlighted a connection that I can't see with a red circle. It's within the harness assembly and shows four wires coming together. Does anyone know what this might physically be?

I tried a few times running the engine in the slip and got the engine to duplicate the shutdown just once. It quit and electric power is gone, then after a few seconds, power is back and alarm sounds. Other than the one shutdown, it just ran every other time with no indication of any trouble.

Does the intermittent nature of the problem sound like a bad connection? Perhaps warming up or vibrating loose from the engine? Could the key switch or breaker behave like this? If the fuel solenoid was acting up, it appears the alarm would still sound since it's in paralell with the solenoid.

[Lodesman]

Originally Posted by Nord Sal

Does the intermittent nature of the problem sound like a bad connection? Perhaps warming up or vibrating loose from the engine? Could the key switch or breaker behave like this? If the fuel solenoid was acting up, it appears the alarm would still sound since it's in paralell with the solenoid.

I'm no expert, but your logic is sound and that's where I would be looking. Is #31 (the lower left circle in the panel diagram) the key switch? I think jumping the "run" circuit at the switch might rule out a problem with the switch - assuming the problem replicates on cue. In practice, I don't know how easy that would be. It does sound like either a vibration issue or possibly a thermal issue - like the heating causes the breaker to open the circuit, but perhaps it's stuck or the spring is shot, so it doesn't "pop" out. You could jump that, but I'd do it with a 20A fuse - or course then if the fuse blows, you'll have another mystery to solve

[Nord Sal]

Yes, #31 is the key switch. My instrument panel is slightly different than the diagram which shows the start and glowplugs all controlled with the key. My panel has a simple "on/off" key with separate pushbutton switches for the glow plugs and the starter.


I was able to duplicate the problem running the boat in the slip. It just cuts out and the power is gone. I was seeing the gages and lights flicker with the engine cutting out and then it died. Power came right back. I was able make it do this a couple times.


I definitely seems like a bad connection opening the circuit.


I've been going thru the connections but was unable to get to all of them yet. I'll be back in a couple of days to continue looking. Everything so far appears reasonably 'bright and tight'. I will keep digging.


I priced the wire to make a new harness and it wouldn't be too much (about $80). I might go that route depending what I find. The harness is 35+ years old, so might be a good idea to replace it for peace of mind. I was thinking of doing a harness project last year, so maybe having this problem is telling me to get with it. Still want to find the actual problem first though.

[jimbunyard]

Typically when problems like you're experiencing rear their ugly heads, the first response is 'bad ground'. Which can be anywhere.

But you're on the right track with the fuel solenoid being the proximate cause.

If the harness looks good, it probably is good. Corrosion at the terminal ends could indicate internal wire corrosion or it may not. A noticable difference of flexibility in adjacent wires of the same gauge usually indicates internal corrosion.

I'd start with disconnecting, closely inspecting, and reconnecting with some sort of lubricant/antioxidant all the accessible multipin harness connectors, as well as checking the tightness and cleanliness of all the terminal ends, especially the higher amperage ones. My preferance is to start at the batteries.

[Nord Sal]

Thanks for the help. I got back to the boat and was able to find the problem. Thought I'd share the results.

I checked all the visible connections and found them to look okay. A little grime and discoloration from age, but nothing loose and no corrosion. I had pulled apart the 8-pin harness connector in the past for inspection and cleaning and looked great when I looked at it.

I was suspicious of the connection I circled and put the question mark on in the diagram above. It was buried in the harness under the intake manifold and high-pressure injection lines. After pulling the wiring harness from underneath all that stuff and pulling the connection out, it looked okay (but a bit strange type of connection).

I went back to the previously 'checked' connections and focused on the wire that brought power from the starter post to the circuit breaker. When I looked really close using a good light and a magnifying glass, I could see a small discoloration underneath the translucent shrink wrap. It really didn't look like much, but it was something plus I was striking out everywhere else and my intuition was telling me I was on the right track so I cut the connector with a pair of dikes and viola! The wire had a couple of broken strands and part just apparently gone and the crimp terminal was partly melted! (See Photo)

I pulled that wire (20" AWG 10) and made a new one. Installed the new wire and cleaned it up yesterday. Boat is now running great.

The failed connection was one of my own that had been working for several years. I think it failed as a result of a combination of: 1) Marginal crimping 2) tension on connection due to shortening of the wire to make new connection 3) Stretching/flexing connection when removing/replacing the starter, and 4) engine vibration esp. as combined with above items 2 and 3. In hindsight, think that I would've been better off to have used a butt connector and a couple inches of new wire back when I made that connection.

The strange connector is in the second photo. It's a large tab connector joining four wires. Power is fed from a #10 wire from key switch which feeds three #14 wires, the tach exciter (same side of connector as #10 feed), water temp/ oil pressure switch alarm circuit and an electric fuel pump. Does anyone know what this type of connector is?

Thanks for the help and support!

[Lodesman]

Congratulations - you've earned yourself a cold one

The unusual connector is called a bullet connector - you can find them in auto-parts stores.

[phorvati]

Congratulations on finding the root cause! What is weird is that your shut off solenoid needs to be energized to run the engine(normally closed). I have that on northern lights generator. It's continuous duty, meaning coil is energized all the time when diesel runs. To me that is more prone to failures and it also draws current all the time. Part of the diesel benefits is that it doesnt need electricity to run. On my Lehman90hp and on westerbeake 40, my solenoid was keeping the shutoff lever normally Open, and coil is intermittent duty and needed to be energized to shut the engine off, so only for few seconds. That way when a wire fails, engine just keeps running as opposed to what happened to you. Then you can always shut it by moving the lever by hand.
Maybe observe the length of play from fully ON, to fully OFF on the lever. And if it happens again, you find a way to over-ride it mechanically so that you can run the engine to get out of potential trouble. Consider getting a replacement one that is normally Open(letting fuel in) and add a push button engine shut off.
Maybe continuous duty solenoids are out there more than I think but too often I get into circumstance where if engine dies I'm pretty f-ed.

[Nord Sal]

Lodesman-not the bullet connector at the end of the lead, but the (disconnected) yellow spade connector with four wires. This is a factory connector with one 10 AWG wire feeding three 14 AWG wires. It looked like the wires were soldered into the connector. If I were to fashion a new harness, I think I'd use a bus for this connection and locate somewhere I could access it without removing anything else.




phorvati - Thanks for your thoughts. Yes! I think this is a bad system for a boat. As you correctly say, A diesel doesn't need electricity to run. Why then, make it need electricity? The only reason I can think is to make it convenient or function like an automobile.

I spoke with a friend who is a long-time diesel mechanic and he said I might just be able to simply remove the solenoid and screw a plug into its place. I have a spare injection pump and am going to pull its solenoid see how the mechanism works to see if that would work. I have a manual stop with a cable pull, I don't need to use the key.

[jimbunyard]

Pretty sure you can just pull out items 2 and 3, shown on page 239 of this catalog, and use the solenoid itself as the 'plug'.

https://www.westerbeke.com/parts%20m...15.0_parts.pdf

[Nord Sal]

Originally Posted by jimbunyard

Pretty sure you can just pull out items 2 and 3, shown on page 239 of this catalog, and use the solenoid itself as the 'plug'.

https://www.westerbeke.com/parts%20m...15.0_parts.pdf

Thanks for the tip! My mechanic friend talked about the plunger but I hadn't looked at the assembly drawing. To my eye, it looks like the energized solenoid will pull the plunger up against the force of the spring opening up to allow fuel to flow and, when power power to the solenoid is eliminated, the spring pushes the plunger down cutting off fuel. Yes?

I sure do wish now that I had asked about this before I re-installed the injection pump a few years ago. Access will be tough, I might have to remove some of the high-pressure fuel lines from the pump to get enough room to turn a wrench. I might be able to come down with a ratchet extension and get a crows foot on it.

It sure seems like a good idea to remove the plunger so that solenoid failure or an electrical problem like I just experienced won't leave me dead in the water, but . . . Is there a downside to removing the plunger from the pump?

I can't think of one other than I now have a redundant shutdown should the cable come loose, that's seems pretty minor given the reliability of the cable. Asking those more experienced than me.

[Lodesman]

I think you might just be defeating the fail-safes (eg. oil-pressure switch) by doing that.

[Nord Sal]

Originally Posted by Lodesman

I think you might just be defeating the fail-safes (eg. oil-pressure switch) by doing that.

Thanks for the thoughts but I wouldn't be eliminating those circuits from what I can tell. They are in parallel with the solenoid circuit and are all branches off of that weird yellow four-wire spade connector fed by the #10 wire. I think eliminating the solenoid branch would turn it into a weird yellow three-wire spade connector fed by the #10 wire.

[jimbunyard]

Originally Posted by Nord Sal

Thanks for the tip! My mechanic friend talked about the plunger but I hadn't looked at the assembly drawing. To my eye, it looks like the energized solenoid will pull the plunger up against the force of the spring opening up to allow fuel to flow and, when power power to the solenoid is eliminated, the spring pushes the plunger down cutting off fuel. Yes?

I sure do wish now that I had asked about this before I re-installed the injection pump a few years ago. Access will be tough, I might have to remove some of the high-pressure fuel lines from the pump to get enough room to turn a wrench. I might be able to come down with a ratchet extension and get a crows foot on it.

It sure seems like a good idea to remove the plunger so that solenoid failure or an electrical problem like I just experienced won't leave me dead in the water, but . . . Is there a downside to removing the plunger from the pump?

I can't think of one other than I now have a redundant shutdown should the cable come loose, that's seems pretty minor given the reliability of the cable. Asking those more experienced than me.

That is the way I too interpret the solenoid's operation.

I don't know enough about the pump to know if there are any potential issues with removing the plunger; the only that come to mind would be if the plunger somehow directed flow from one port to another. This would normally be done with drillings in the plunger itself; if there are none it is unlikely that it performs that function.

If it were me, I'd just look at it and make an educated guess. A good diesel injection pump rebuilder should be able to tell you for sure if you can tell him the pump manufacturer and model.

Regarding the cable shutoff, even if there is a problem with the cable, the engine can still be shut down with the engine mounted lever.

Originally Posted by Lodesman

I think you might just be defeating the fail-safes (eg. oil-pressure switch) by doing that.

If the engine is fitted with a high temp/low oil pressure shutdown system, instead of just an alarm, you're more than likely correct. Though an externally mounted solenoid could almost certainly be arranged to use the same signals to shut the engine down in the event of a problem...