Yanmar Diesel Engine

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
Any one here familiar with a 4C type Diesel Engine.

Need some info on the location of,
1. Oil pressure sender
2. Temp sender
3. Tacho sensor.

I have a job to correct a wire harness as the harness was wired wrong and some wires are corroded.
 

Felo

Joined Feb 20, 2012
91
Hi,

I used to do maintenance on FG WILSON generator sets for a long time, unfortunately don't have any manuals but I may still help.

1- The oil pressure switch is commonly located on a side of the engine block (ribs) it is also normaly marked so it shouldn't be a problem finding it. It looks like a big headed bolt with a one terminal/wire output when the engine is not running the terminal is closed with GND, when running is open.

2- Temperature sensor is located near the water pump close to the radiator, it works similar as a PTC.

3- The tach signal is sent by a magnetic pick-up bolted on top on the engine flywheel, it outputs a sine wave of aproximately 2-3 Vpp.

For controlling start-stop cycles of the engine the most important thing is the oil pressure, the other sensors may be used only for monitoring purposes, but I thing its a good idea to use the pickup to detect overspeed and shut the fuel in case of.

Hope it helps
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
I use to do this a lot, but since I have stopped it's been years and I am disappointed to say that I have lost touch.
:(
I still remember where these buggers are located but this thing has two of each :eek:

Two temp senders
Two oil pressure senders
Did not check but I think I saw another tacho at the gear Assy.

Cause I did a check on the harness continuity and to my surprise the tacho sensor which is located near the oil sender right before the Gear Assy has a direct connection to the ground in the panel.

Now even a moron would know that its not how it is supposed to be. I mean this thing has been checked by I would say wannabe's now last week. They took a week and ended up taking the panel to God knows where three times and saying that Panel is OK. And the harness is faulty.

Well DUH ! The panel is like it is made by a five year old. I doubt it is connected the proper way, I did a routine check on loose connections and I even got confused about how it was wired, as I have seen and made some my self in the old days.
So why the heck they did not check the harness.

I know why, cause these morons have no idea on using a DMM the proper way to do a routine check on such systems. They have no theoretical back ground on any sorta electrical system.

I would say this boat was and has been wired wrong from the beginning cause I cannot find any one who use to work in it knows or even remembers if the panel worked before. From the very first look at the panel I said it was made in Lanka.

Guess what. The New owner said the engine was installed in Lanka

:DI am freakin genius.

Anyways, Now I know the whole thing did not work and due to this reason no one was able to get it working any time soon. Previous parties took weeks to say anything. I took less than 2 hours to yank out the harness, find corroded wires plus burned ones with wrong connections.

No meter works except for the lights. But still somebody bought it from somebody else and the new owner wants it to be in working conditions. Any company here would just charge thru the roof and replace with original harness and panel and believe me, it would cost 5 times more than what I would to fix it using brand new meters & renew the extension harness.

I have not seen two senders mounted next to each other before, I guess this might be the new types as I have not worked on gensets and Engines for like 6 years or more.

I guess now I am going to the old habit of visiting luxury yachts and safari's again, cause I got couple of jobs waiting after this one.

They even want me to join the Sun Travels as a chief Engineer. I doubt I would except the offer cause I like to have spare time to do my R&D's

I did not take the cam , cause I thought it would be just a panel fault. But I will take some pics tomorrow and post it to clarify the sender's.

I have the panel with me, but am a bit tired since I was up last night fixing some stuffs.

I'll get some sleep for a few hours and come back with the panel pics.

I like you guys to fill in for me. I mean the knowledge gaps I might need.
And also like you to comment on this childish panel too. It will be a good for a laugh. Come back after a few hours.

G'night.
 
Last edited:

Paul Kerry

Joined Jan 9, 2012
36
The ? is the oil pressure switch for the indicator lamp and or possibly alarm

Hope this helps

Paul
PS nerde is pointing out that whoever wired it only had red wire!
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
Hmm....Just as I thought.
They say from the beginning the lights works but the gauges don't.

I wanted to make sure that they are a sender and an alarm sensor.
This is simple..
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
I know that Paul.

I am thinking of renewing the whole thing.

So I bought 600 feet of 2.5mm Multi-strand DC cable to extend the harness.

I am thinking of making a descent panel for it.

How would you recommended I should go abt it.

I can make as in the Yanmar manual

In the panel u can see Auto / Manual switch .....What is that for ?
 

Paul Kerry

Joined Jan 9, 2012
36
I know that Paul.

I am thinking of renewing the whole thing.

So I bought 600 feet of 2.5mm Multi-strand DC cable to extend the harness.

I am thinking of making a descent panel for it.

How would you recommended I should go abt it.

I can make as in the Yanmar manual

In the panel u can see Auto / Manual switch .....What is that for ?
I'm guessing that the Auto / Manual switch changes the mode of operation between Auto start on power failure or not.

I'd be tempted to use an aluminum or steel box as it will give you something solid to anchor cable glands to.

Another option could be to cut most of the original front panel out, leaving a lip all the way around to mount an infill panel on to. Probably less work on this one :)

Just had another look at your pictures, I have a feeling that the item that you think is the tacho sensor is in fact the fuel shut off. The tacho is probably driven from an output on the alternator.

Regards

Paul
 
Last edited:

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
I'm guessing that the Auto / Manual switch changes the mode of operation between Auto start on power failure or not.
The is no Generator so what power failure or auto start. It's just a freakin fishing boat :D

I'd be tempted to use an aluminum or steel box as it will give you something solid to anchor cable glands to.
l
Sorry ....No go here.


Another option could be to cut most of the original front panel out, leaving a lip all the way around to mount an infill panel on to. Probably less work on this onel
So u think this panel is a bit over kill huh !.
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
Just had another look at your pictures, I have a feeling that the item that you think is the tacho sensor is in fact the fuel shut off. The tacho is probably driven from an output on the alternator.
Ya ! That is what I was thinking, when I saw a the alternator connection.
And this this not having a visible fly wheel I doubt it was the tacho one...

Thanks Mate for clearing that..

Can u tell me what does a fuel shut off does. ?
 

Paul Kerry

Joined Jan 9, 2012
36
The is no Generator so what power failure or auto start. It's just a freakin fishing boat :D



Sorry ....No go here.




So u think this panel is a bit over kill huh !.
I was only guessing on the switch, I'm more used to agricultural and generators!

The panel just looks messy! I'm sure you more than likely wouldn't want to put your name to it ;)

If the fuel shut-off is not powered the engine will not start and stay running, to stop the engine you just remove the power to it.
 
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