1993 Kohler 6.5CZ23 only runs while holding start button

[jeffnnoble]

Thanks for reading.
Here is the story. Out on the water genny running fine for about 5 hours start the main engines to head back to the slip, (about a 30 minute trip). Upon return to the slip I realize the genny is not running any longer. For some reason it shut down in that 30 minutes. Being late and having to working the morning figured I'd look into it later. So here is what I have done and know.
* Generator RUNS while holding either switch (switch on the unit or the remote switch on the breaker panel) but stops running as soon as you quit holding either switch in the start position.
*The oil level is full
* All breakers on
*Both of the fuses next to the hour meter have continuity from one end to the other
*No sign of ant loose, broken, or burnt wires.
*The strainer is clean and clear.
*While holding the start switch and the generator is running it is pumping water out of the discharge
*While holding the start switch and the generator is running it IS NOT producing/outputting enough power to make anything plugged into any of the 110 outlets work.
*No sign of any corrosion on any connection or control board.

*OBSERVATION of the large control board it has 4 LED's that are numbered locations are bottom (LED1) mid right (LED2) upper Left(LED3) Upper Right (LED4) I believe the control board is part# A-229388. I also believe has been replaced by C-229388
-While holding the start button (During engine crank and run) LED's 2 and 3 illuminate.
-Upon release of the start button LED4 blinks 1 time immediately
-LED1 is not illuminating at all during this process.

I am hopeful that someone reading this will know what the issue is.

I also saw in some of the other threads where Viper had posted the service manual (TP-5338), And was hopeful Viper could repost because when I click the link it is responding with destination site not found.

Thanks to everyone that takes the time to read this and reach out.

Jeff
1993 Carver 350 Aft
Grand Haven Mi

[RobGunn]

My Kohler Generator is doing the exact same. I have a guy working on it and he tells me the low oil pressure safety switch is bad. This switch detects oil pressure and will shut down the unit if the pressure gets to low. In my case, the oil pressure in the unit is good but the switch itself is faulty and causing the shutdown issue.
Let us know what you find out.

[plittle2005]

Agree. I have to hold my switch just briefly, 1-2 seconds until the oil pressure comes up, otherwise shuts down.

Phil Little
'92 350 AC Gas

[jeffnnoble]

Phil, Thanks for the suggestion. I have held the start button for as long as 10 seconds after the generator has started. once while checking discharge water flow, once checking LED's on the board. And again for wishful thinking. Unfortunately it didn't remain running after letting go of the start button.

[jeffnnoble]

Rob, Was the oil pressure switch replaced, and now your generator runs as it should? Asking because they are only about $20 and not too bad to replace. I just didn't want to ge into the mode of throwing parts at it, Thinking perhaps the Control Board LED's may offer insight?

[bud37]

Sometimes you can fool the control board at the oil pressure sensor, to test you need to figure out how the sensor reacts to oil pressure.

For sure though if it turns out to be the sensor shutting the unit down you would be well advised to check the oil pressure with a gage if possible to make sure there is actually pressure while the unit is running. Don't just assume the sensor is bad.

[RobGunn]

Jeff, I dont have my generator back yet to know if changing the switch took care of the issue. I was only stating what my guy has told me he found and is going to do to fix my issue. I assume he will get done soon and prove out the fix. One point I do want to make is I installed a "T" on the oil line near the oil pressure switch and installed a actual gage that I can read to verify what the oil pressure is regardless of the sensor. I do believe that the sensor could be by-passed if needed, however I do not know if its normally open or normally closed. A wiring diagram would answer that.

[Midnightsun]

The oil pressure sensor simply makes contact to ground when pressure is detected. As mentioned, make sure there is oil pressure before testing the switch. Unless there was catastrophic failure of the oil pump which I seriously doubt, just check to make sure you have enough oil via the dipstick. If the level is good, just disconnect the wire from the sensor and ground it to the engine block. If the shut down issue is solved then this is your problem.

Now test the switch to see if it actually is working or if it has failed.

[km1125]

You can also measure the current switch for continuity when the generator is NOT running. If you get "0" ohms (short), then it's normally closed and would/should open when the genset is running. If it's open when not running then it would/should short when the genset is running (as Hans notes).

[tomschauer]

Its sounds more like a failed capacitor than an oil pressure switch.