Yacht Deviced YDEG-04 + Kohler 6EOD ADC 2100

[STB]

Hey All,

This is just a note for anyone it may help.

The Kohler 6EOD generator (and likely any others from Kohler using the ADC 2100, among others) has a digital gauge kit that uses the standard CAN/J1939 interface.

I didn't want to pay ~$800-$900 for the Kohler digital gauge kit, which contains a single multi-purpose digital gauge, especially since I'd need two of then to have one at each helm. So, I ordered the Yacht Devices YDEG-04 to take the data from the J1939 interface and put it onto my NMEA2000 (ST-NG) bus where my chart plotters and Raymarine i70 and other instrument can show it, as can my OpenCPN instances.

I hooked CAN_H to pin 1 (yellow) and CAN_L to pin 2 (Green) and the cable shield to pin 9 of the genset's Customer Interface Connector (CIC).

That, by itself didn't work, so I added a 120-Ohm resistor across the CAN_H and CAN_L on the second and otherwise unused of the "Y" connectors on the YDEG-04, and magic happened.

A 120-Ohm terminating resistor is typical for each side of a CAN bus to dampen signal reflections on the wire. In this case, after poking for a bit at the wires coming from the controller, I think the current through the resistor somehow turns on the interface on the controller. I didn't see much until it was there.

I mention this because the instructions with the YDEG-04 were seemingly written with an underlying assumption that one is attaching to an existing and properly terminated CAN bus versus creating a new one connecting the YDEG-04 and the genset. As a result, they don't mention that resistor as part of the installation instructions.

If you are wondering why my genset hours show as 2hrs in the attached picture, it is because this display doesn't show fractions for hours and because I replaced the controller on the genset 2.1 operating hours ago, at which time the indicated hours became 0. I did sticker the generator just above where it displays the hours with the offset as well as noted it in my operation and maintenance logs.

The genset had started acting weird, sometimes not starting or stopping from remote, sometimes throwing random errors at start (and then running fine), and sometimes showing fewer operating hours than actual. A new controller seems to have cured these erratic behaviors.

 

[Art]

Our low hour 1977 Kohler 7.5 kW gen set [when it is cold] always starts and runs fine. But... it has begun to more often than not suddenly shut down for no known reason [after running from 30 minutes to over an hour - sometimes it does nor suddenly stop]. Once it suddenly stops it will not start again for about an hour after stopping. Oil pressure stay up and it does not at all get too hot.

Input appreciated!

 

[STB]

Hi Art,

Attached is the schematic and ladder diagram for a similar genset I once worked on. It was also a 7.5k Kohler diesel, original equipment in a boat built in 1977. It may not be yours, but hopefully it is close.

Once that genset is running the things that can stop it are.loss of oil pressure, water temperature too high, loss of 120v output, loss of fuel, or something along the wiring path for those sensors being bad, including the CR or 1CR relays.

How does the genset stop when it does? A hard stop or rough running or sputtering and then a stop?" Air getting into the fuel is always a possibility, for example if a filter is clogged and it is pulling air on the vacuum side. Or, if the primary fuel filter has water in it and the ball inside is floating up and potentially shutting off the fuel. Etc.

You might want to check the wiring for the oil and water safety switches and make sure the wires, connections to the board, and terminal rings look good, as dontelhe sensors.

If you've got an IR temp gun and a cheap manual oil pressure gauge from harbor freight or otherwise, you can try disabling the water and oil safety switches and monitoring those parameters manually and seeing what happens. If it doesn't die, you can divide and conquer and reattach one switch at a time -- or replace both -- and see what happens. (You cannot also.live dangerously and not monitor while testing this way...but what if it is a real problem?)

Beyond that, try looking at the relays and sockets. Make sure the relays look clean and good and that the relays are sitting tightly in the sockets. They often look bad, if they are.

Beyond that, I think you may need to catch it in the act. Put a meter and start poking around, trying to catch it in the act. Or replacing the relays and seeing what happens.

It also can't hurt to look over the board and see if anything looks toasty and resolder or replace it as needed.

I hope this helps. You may also want to try posting in the vintage Kohler forum on SmokStak.

Happy Hunting!
-Greg

 

[Art]

Hi Greg

Thanks for the posted plethora of what ifs, suggestions and plan/spec details! I'm going to copy your post and keep on boat. Already have full spec book copy for 1977 "gasoline" 7.5 Kohler. But, have now copied the pages you provided and will staple them to copy of your post.

In answer to your question - "How does the genset stop when it does? A hard stop or rough running or sputtering and then a stop?"

99.9% of the time... When the 1977 7.5 kW Kohler gen set suddenly quits it is a dead stop [instant - no hiccups nor belches; it just stops]. That said, once or twice I did hear it stumble for an instant and then resume a solid running condition... that was before it did a dead stop some 30 minutes later.

One item that makes us never leave the salon [where genset switches on the electric panel exists]: This gen set has a "load activated" starter system. So... when the sudden dead stop happens the breaker switch loads are still "on" - therefore the gen set starter immediately begins to try and restart the gen set. Seeing as the gen set never starts again until an hour + has passed since the sudden shut down... well, you get the picture. We'd better be right near to completely shut down the system to stop activation of the starter or BIG problems could happed. Such as: Burned out starter and even possibility of a fire.

Here's a couple items [again Thanks!]:

 

[Art]

Greg - The problem with my getting the 1977 7.5 kW Kohler gen set problem rectified by an expert is two fold.

1. Seems to be [I've been seeking one for a couple years] no 1977 Kohler gen set expert is available anywhere near up in SF Delta where we dock boat, cruise and anchor out for swimming and play time in warm fresh water. That's 100 hwy miles from our home.

2. I do know an expert who works in a marine engine shop in SF Bay area. Unfortunately... it's a full day cruise just to get there. And, I simply can't find the time to do a back and forth... but guess I had better find time to do so! Because - I'll try some things you mentioned... but not knowing much about the intricacies of that ol' gen set I could really get things out of wack if I pry in too deeply.

Thanks for the input!

Art

 

[STB]

Hi Art,

Okay. So yours is gas vs the one I worked on which was diesel. But, the back end looks almost identical.

Next time you are there can you get a picture of the name plate on the genset that can the spec number, etc, Inwant to see ifnI can find a schematic.

It sounds like the controller is tripping on something because it stops hard. Of course, if it's putters, outout voltage drops, and then the controller sees that and shuts down, sputtering does get truncated.

Does it don't at idle? Or just under load? How is the output voltage and frequency? Do you have a meter than can check?

Also, SmokStak is a forum, not unlike thinning, with q section dedicated to older Kohler gensets. Some of those folks know them inside and out. I'd post there also.

 

[Art]

Hi Art,

Okay. So yours is gas vs the one I worked on which was diesel. But, the back end looks almost identical [probably is].

Next time you are there can you get a picture of the name plate on the genset that can the spec number, etc, Inwant to see ifnI can find a schematic. [Believe I have schematic - tried to add in earlier post but too big for TF to copy]

It sounds like the controller is tripping on something because it stops hard [Yup]. Of course, if it's putters, outout voltage drops, and then the controller sees that and shuts down, sputtering does get truncated.

Does it don't at idle? Or just under load? [It must be under load or it automatically shuts down... because it's load activated] [How is the output voltage and frequency? [Good] Do you have a meter than can check? [Both an mechanic and I checked]

Also, SmokStak is a forum, not unlike thinning, with q section dedicated to older Kohler gensets. Some of those folks know them inside and out. I'd post there also. [Looking into SmokStak]

Please see [answers] in your post above

 

[STB]

Hi Art,

I looked at the schematic you sent. Are you sure that is for the right genset? It is a very advanced controller for 1977. Not impossibly so, but more curve leading than I'd expect from a Kohler.

In any case, I took a look at the schematic. The inputs are basically the same...oil pressure, water temp....and cylinder head temp. It looks like, if any of those switches trip, it starts a 30 second timer on a time delay relay, which in turn turns off the run relay, among other things.

It is a little strange that it seems to take 30 seconds to shut off with low oil pressure or high temp -- that's a darn long time in my book. But, the schematic is clear as day.

Since this thing is running so long before shutting down, my bet is that one of the temperature switches is tripping. Since a tripped switch is closed, you can test for this by leaving the wire off the switch and wrapped temporarily in electrical tape or otherwise insulated. If the problem doesn't occur with the switch removed, you found the reason for reason for shutdown.

It could also be the oil pressure switch tripping. You can test for this the same way.

I thinknyou mentioned that you verified oikcpressure with a gauge. Given that, I'd be confident in running it without the oil pressure switch long enough to test.

But, are we sure the unit isn't legit overheating? For example, a clogged up heat exchanger? Bad thermostat that isn't opening? Clogged up strainer or water flow? Bad raw water pump or water pump impeller?

In other words, how do we know the genset isn't legit saving itself and you from overheating and a new head gasket or whole new engine?

Since there is a 30 second delay between a switch triggering and the shutdown, if you are patient, you can also watch the switch trip. Set up a multimeter looking for 12v between some 12v source and the top of the senders and wait. 30 seconds before the shutdown, you should see 12v on the switch that triggers it. If you can set up a couple of meters, one on each temp switch. If you can scare uo a third meter from someone on the dock, watch both temp senders and the oil pressure sender (ignore the reading until the genset gets going).

If the shutdown shouldn't be happening, my 1st bet is a bad temp switch (head or coolant) or connection. My 2nd bet is a bad oil pressure switch or connection. My final bet is a bad relay.

But, I am concerned you might be cooling inefficiently and running hot causing the shutdown for all the right reasons.

If your coolant line isn't getting hot on its way to the heat exchanger, your thermostat may be bad. If it isn't getting cooler coming back into the engine, the heat exchanger or raw water pump or filter or water pump may have problems.

It shouldn't be hard to isolate the problem to a switch, which will point to that swi4xhbor a related cause.

If it fails without any of the switches tripping, that is pointing back toward the relays. We can talk about how to debug that if we get there. It won't be too bad. But, before we do, let's check into the low hanging and seemingly more likely fruit w.r.t. isolating if a sendernis triggering the shutdown and if it is right or wrong to do so.

Happy hunting!

 

[Art]

Thanks Greg - I'll print that post too. With boat 100 miles away and four in family from Texas coming to stay in our house for a while it will be some time before I can check out the gen set... regarding many of the items you mention.

BTW - Genset does not falter in producing power before sudden shut down nor does it at all seem to over heat. I've been right next to it more than twice before and with tools checked both of those items carefully.

That is the schematic for our gen set. It was top of the line in 1977. Tollycraft boat builders used the best in pretty much everything.

 

[STB]

Hey Art,

Maybe you'll get lucky and it is just a bad oil/temp switch or a loose connection on one. That would be easy.

But, the thing about overheating is that there really aren't any external clues that a genset is at operating temperature vs 15 degrees over. Neither the exhaust water nor exhaust will look different. It won't sound or run different. And, it won't feel different from nearby.

I think that genset has a visible oil pressure gauge? So I'm guessing you checked the pressure there. Given that, I'm willing to believe if the oil pressure switch is triggering the shutdown, it is more likely to be a bad switch or connection than a problem with oil pressure.

But, I don't think the genset has an external temp gauge? So, how do we know temperature isn't a real problem?

The reason I keep poking at temperature is that a shutdown after 30-45 min of loaded runtime is pretty typical of a problem with the cooling system. This is especially true if if shutdown again very quickly if restarted, but again starts up and runs for a while after a "rest" during which it cools down.

If I understand your trouble report correctly, it runs for a long time before shutting down the 1st time, but then when it tries to auto-restart, it shuts right down, so you have to be there to shut it off-off. But, after a rest, when you try again, it'll run for a while -- then wash, rinse, repeat. This, to me, sounds like it is running for longer after it cools down than when it is already hot.

At any rate, when you get to it, hit the forum back up again and we'll take it from there.

 

[Art]

Greg - Another little factor is that for over a decade, many years before this sudden shut down circumstance began to happen, once the gen set had run for any length of time, even for 15 minutes or for hours, it never would start again until about an hour after I had purposefully shut it down... kinda strange. Reason I'm sure it's not overheating is because I get real close and personal with the Kohler. I shoot all areas of the unit with IR gun and put my hands everywhere on the unit as well as in the exhaust water as it comes out the side of boat. No extra heat is occurring in any area. And, yes it has oil pressure gauge on the engine. It I always keep it set at 20 lbs which is exactly what Kohler recommends.

Planning to let you know more when I get chance to delve in further. With commitments oncoming and 100 mile distance boat is from home that will be in July at earliest.

Cheers!

Art

 

[OldDan1943]

I know nothing about Kohler gen sets.
My NL had the same problem, no start after running a while. Next day, still would not start. Called the tech, he came out, did some checking, replace the temp sensor. Presto, no more problems.
Now I carry spare oil pressure and temp sensors. Same with my Cummins.

One of those things, it chose the most in opportune time to fail.

 

[STB]

Ah. Perfect. If you've shot it with the IR gun, you have the answer on that.

If disconnect those three sensors, keep an eye on it, and see what happens. Then, if it fails, we know to look upstream. Otherwise you can add them back one at a time until finding the responsible party.

Good luck (when you get there!)

 

[OldDan1943]

I forgot, I have also added high overboard temp alarm. It just alarms, no shut down. It will indicate a clogged sea strainer or failed impeller.
My old farts brain has forgotten the maker of this alarm. I do believe it was discussed in the trawler forum previously otherwise I would not have known about it.

 

[STB]

I just wanted to update the thread that I needed to do one more thing to complete the package. The oil pressure being transmitted by the genset was bogus. It essentially always reported 43.5psi.

To get a real oil pressure, I needed to install Kohler Part #GM32112-KP1 in place of the existing oil pressure switch. It is a combination oil pressure sender and LOP switch marketed for newer Kohler gensets.

The connector for it was in the harness, but unused. It was the only one that fit. So, I unplugged and removed the LOP switch, burying the wire to it back in the harness, installed the combination switch/sender, and dug out and plugged in the wire that was intended for it. The instructions mentioned only a bunch of newer models, but were largely applicable.

The only discrepancies I noted between the installation and the instructions for the other units were that the LOP switch was located in a different location on the unit, and I didn't need the right angle adapter. I didn't check the wire numbers, I just unplugged the ones going to the old switch and used what fit the new one, so I can't comment about their correctness.

 

[wkearney99]

I didn't want to pay ~$800-$900 for the Kohler digital gauge kit, which contains a single multi-purpose digital gauge, especially since I'd need two of then to have one at each helm. So, I ordered the Yacht Devices YDEG-04 to take the data from the J1939 interface and put it onto my NMEA2000 (ST-NG) bus where my chart plotters and Raymarine i70 and other instrument can show it, as can my OpenCPN instances.

I hooked CAN_H to pin 1 (yellow) and CAN_L to pin 2 (Green) and the cable shield to pin 9 of the genset's Customer Interface Connector (CIC).

That, by itself didn't work, so I added a 120-Ohm resistor across the CAN_H and CAN_L on the second and otherwise unused of the "Y" connectors on the YDEG-04, and magic happened.

A 120-Ohm terminating resistor is typical for each side of a CAN bus to dampen signal reflections on the wire. In this case, after poking for a bit at the wires coming from the controller, I think the current through the resistor somehow turns on the interface on the controller. I didn't see much until it was there.

I mention this because the instructions with the YDEG-04 were seemingly written with an underlying assumption that one is attaching to an existing and properly terminated CAN bus versus creating a new one connecting the YDEG-04 and the genset. As a result, they don't mention that resistor as part of the installation instructions.

Have you reached out to Yacht Devices? I've gotten very useful information from them. I'm guessing they could address your hours situation pretty easily with a config change in the YDEG.

I'm exchanging e-mail with them about adding an interface for my MicroAir AC controller boards. The FX2 controller boards have CAN bus, but I may need to massage/filter the PGNs before passing them to the main N2K bus. The Yacht Devices stuff is very versatile for this.

I only wish my ancient Onan MDKAZ generator had CAN bus support! I'd love to have more intelligent monitoring and control of it.