Yanmar Diesel Engine

There is no Engine stop solenoid.

When I asked the captain to shut off the engine he went running in to the engine compartment.

He said it is how it shuts off.

By Hand.

R!f@@ said:

There is no Engine stop solenoid.

When I asked the captain to shut off the engine he went running in to the engine compartment.

He said it is how it shuts off.

By Hand.

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I think someone has taken the plunger out as it's a solenoid valve.

Paul Kerry said:

I think someone has taken the plunger out as it's a solenoid valve.

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I got a Volvo Penta, and to turn off the engine, I'm pulling a steel wire. This stops the fuel to the engine. When engine has stopped, I turn the key to the off position. This is original from the fabric in 1982 or '83.

nerdegutta said:

I got a Volvo Penta, and to turn off the engine, I'm pulling a steel wire. This stops the fuel to the engine. When engine has stopped, I turn the key to the off position. This is original from the fabric in 1982 or '83.

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Same with my 1958 Nuffield tractor!

Got into reading the Manuals.

Thanks Jens

So now I got me a Yanmar 4CH Engine which has around 11 wires in tbe harness.
It's around 3 am in the morning, good time to lay out the wires on the road. Routing 36 feet of 11 DC cables into a conduit in the middle of the road in the middle of the night tends to get the law & order guys on patrol to get interested during these days....no. Had fun though.

Extension is done. Now it's time to take a good look at the Panel.

Oh by the way, I looked up the name on the panel via google and all I got was a state with tourist tour agents and stuff .....

I guess made in China is not the only country I have to deal with. Eh!.

This is the first time I got a made in Friggin' Srilanka

Everybody said Panel is OK..!

So I never bothered to check thoroughly, just that the lights light up when needed. So I thought it was OK.

Man-O-man I was stupid. I should have looked thoroughly, and I thought Chinese guys does some stupid things but this is freakin' ridiculous.

First Issue found when I gave deep look into the connection. The temp and oil Lamp are parallel connected.

Tacho Meter has a 20A fuse. Why ? God Knows.

Second Fuse goes to the 3 low power bulbs but fuse rated at 20A.

Third Problem is that from the panel photo u can see the temp meter has a label saying "24V", but in the back it says 12V so does the Oil meter.



That got me mad....really mad... stupid (*^*&%*%*&%..why do they do this and who in the right mind buys this and to be boldly proud of the Maldivians, "me" being one said the bloody panel is good. I mean how ever did the previous party checked it and said it's "OK".

Is that we do not have qualified people doing this. And who in the right mind would give these kinda buggers such jobs. This is pathetic..for once I am truly pissed at my people.

Sheeeeesh ! What are they learning. They have all kinda certificates and they occupy all kinda high ranking jobs and for what ?

OK. So Me being pissed, I dismantled the whole thing. Never gave a second thought. Cut out all the wires and stripped the whole thing.

Checked the Meters. Giving 24V and the temp does not respond....
Well !!! Duh ! ..Bugger....it says 12V...so stripped it and found it like this



Burned !

The Oil meter works some what but it is jumping and it too is for 12V system.

But this 4CH is a 24V system.....ooooops..oh crap! just remembered...I got to check the alternator today.

But before I go...the RPM meter is rated properly




Can any one tell me where exactly the tacho wire connects to from the below Picture



The connection marks " + , 24W, 12W (empty), - "

So which is which..

Me going out to check the Alternator.....

Man am I going to charge these buggers good ...!

Suspect the + is 24V power, -- is Gnd, 24W will be the Tacho signal & will probably be a terminal on the altenator picking the AC power from a winding before the Diodes.

This is a tacho of a Volvo marine diesel, it uses a seperate gear driven Tacho generator, which feeds AC to G & W. 24 DC power to+24V & -- Neg.

debe said:

Suspect the + is 24V power, -- is Gnd, 24W will be the Tacho signal & will probably be a terminal on the altenator picking the AC power from a winding before the Diodes.

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Just the info I needed.
Thanks debe

I just came home from doing some measurements on the senders.

Water temp sender is at 800Ω
Water temp Sw is Open

Oil sender is at 45Ω
Oil pressure Sw is closed ( 0Ω )

The sensor at the gear which I thought was the tacho shows 80Ω

Cannot locate a tacho any where.

So I guess the RPM uses the "L" wire to measure RPM.....Am I right here ?

Can u guys comment on the resistance measurements for me, before I go out and buy some meters.

Oh and by the way, I went to the Yanmar centre here and checked the original panel. It seems the original has just the RPM and the water temp meters and the rest uses light as warning indicators.

And it's layout is waaaaaaaay different from the lanka mogambo make.!

Oil press at 0 for 45ohm about right, will probably go to about 100/110 ohms at mid range of pressure gauge. Water temp 800ohm cold, about 40ohms very hot. Water temp Switch open. Will close in over temperature situation. Oil pressure swich is closed with no oil pressure, most open circuit above 15Psi.

The sensor on the gearbox that reads 80 ohms. What does it do with the engine running? does the resistance change or does it put out a small AC voltage. If its an AC voltage it probably is the tacho sender. If not & its changing resistance then it will either be a Gear oil pressure or Temp sensor. Perhaps a picture of the rear of the Altenator.

Daryl, U are a life saver. Am glad to get hang of these things again.
I will check the last one, the captain was away so I could not start her up.

The alternator photo's are above but if u prefer.

This is what the inst panel circuit diag should look like. The Altenator only has 3 terminals & asuming it has an internal voltage regulator. Then + is to battery, E goes to ground? need to check this. The remaining terminal will be for Charge lamp L. Check front of engine that there isnt a Tacho sender there? May be driven of front of cam shaft.

The diagram is how I had in mind.

Charge lamp cannot be a tacho pulse, right ?

I tried very hard but there does not seem to be any more sensor mounted.

One more q.

I know that the buzzer will sound when the key is turned on but how does it turn off when the engine is running. I don't think the temp sensor turns on as soon as engine is started.

Doesn't the temp switch turns when the temp reaches a certain high value ?

The buzzer could be tied to your oil pressure switch.

So I finished the harness..extension...!



But I did it my way. My way is " I am never going back to that boat again "
That's why I buy all kinda stuff. Me got some kinda red colored grease kinda thingy spray bottle that says it stops salt and rust corrosion on battery terminals in and protects them in marine environment...!

I took apart the whole connector and did it properly...atleast it is how I feel it should be done

Today I went around to find me some gauges and it seems they have what they have, if it works , it works, if not, ur loss. who cares ?

They have all kinda stuff but when I want something it's always out of stock.

So back to the bench. Took apart them meters..



Found the resistors burned. I guess they didn't last long on 24V.



So I am trying to learn how these buggers actually work. I can see all the connections.



According to debe and did some math and use a pot to simulate the senders. But the resistors are showing confusing values...

One is showing 0.6MΩ and the other respective one is open.(connected in series with the B+ and meter , so it's a dropping resistor.)

The second one is like 300Ω and 320Ω. ( these ones are connected as shunts. I mean across the sensor and ground.

So how does this meters work...
The coil resistance is different from the oil to water meter. But the resistors looks the same.

I can't seem to keep the water temp meter needle steady...it's either freezing or burning.

Ok..I did a comparison and the two meter coil resistance are not the same but the resistor arrangement are similar

The two low value ones (300Ω & 320Ω) are connected as shunt with the sensor terminal.

The meter Vcc goes via resistor..... both looks the same but I measure 0.6MΩ and 300Ω.

The coding is f***d up I think

Heres amended circuit, add 2 diodes to buzzer & atach to temp switch & oil switch. The buzzer will sound at switch on & go off when oil pressure up after eng running. Will then only sound if over temp or oil pressure too low. You are absolutely sure there is no tacho sender on the front of the engine. The later version Yanmar 4CHE3 has a 2 wire sender which senses the ring gear teeth on the flywheel. But i dont see one on your motor.

I doubt the tacho will work of the Charge lamp circuit. Heres a typical 12V temp gauge & they are a crossfield type instrument. The resistors are going to be a higher value for 24V. The only way you will calibrate the meter to the sender, is put the sender in known water temps & read of the resistance. Then use your variable resistor, thats how its normaly done.

debe said:

Heres amended circuit, add 2 diodes to buzzer & atach to temp switch & oil switch. The buzzer will sound at switch on & go off when oil pressure up after eng running. Will then only sound if over temp or oil pressure too low. You are absolutely sure there is no tacho sender on the front of the engine. The later version Yanmar 4CHE3 has a 2 wire sender which senses the ring gear teeth on the flywheel. But i dont see one on your motor.

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I was just thinking of that u know.

I managed to repair the oil pressure meter. I used a 330Ω shunt and applied 12V to the meter.
Used a 200Ω pot to simulate the sender and it worked .

Now for the temp..

I like to know is the temp meter different from the oil press meter ?