Kohler generator wont start

[exponent]

I am working on a Kohler 56 foot boat. The Kohler generator model 23EOZD will not start. It doesnt even turn over. The battery is good and the control power is functional. When I press run it briefly flashes CC1 and I can hear the fuel pump run for a short time. The display then changes to OC which is Over Crank. According to the manual the generator should go through the CC1-CC2-CC3 process where each CC represents an attempt by the starter to start the generator set. In my case it only goes CC1. I thought I would check here and see if anyone has any ideas as to how to proceed.

[km1125]

Do you know how it was last shut down?

I would start by shutting off main power first and let any existing errors clear out. Then push and hold start/run for a bit and see if it actually cranks.

I just went through this with a friend. He had pushed run and stop in some weird combo and got the unit locked up and it wouldn't start. Cleared everything out and then it started just with holding down the run/start switch.

[exponent]

I dont know how it was last shut down. I had disconnected power and let it sit for a while to as you say clear errors, The situation is now that genset wont crank. The controller displays CC1 and then after 2 seconds displays OC. OC is over crank and means the engine filed to start after 3 cranks but there wasnt three attempts only 1 and it never turned over. I do hear the fuel pump come on when I attempts to start but that is the only response.

[km1125]

That just sounds so much like his issue.

He had run the genset a few days before and it ran OK, then he couldn't start it... it would not crank. Could hear the fuel pump run (prime) but would not crank. I started suspecting the actual starter or the starter relays or solenoid. I had him open the genset cover and swap the relays hoping that would change things and nothing was better. We even thought there might be a dedicated battery for the genset that was low or bad, but that wasn't the case as it was served off the stbd mains. He had an older diesel genset before that needed the glowplug preheat when it was cold, so he was pushing the bottom button (off/prime/preheat) before run/start and that was somehow confusing the system. Even doing it the right way after that would not work. He did not have the controller display, only the flashing light and it was flashing codes when he tried to start.

Most generators will not crank until an "overcrank" alarm has been cleared out of the system.

However, that said...

Here is the Cummins/Onan troubleshooting steps for and "Overcrank" condition:

Onan_overcrank.jpg

[KeithS]

Usually no crank and setting of the OC code without going through the 3 attempts is a sign of low voltage. If the voltage drops below 9.6 volts while cranking, the controller shuts down. Check with a voltmeter while attempting to crank and see what you have.

[exponent]

Battery was tested and with both a voltmeter and a load tester, No problems with battery as it was replaced just a few months back. The problem is the engine never attempts to crank at all, it flashes CC1 for a couple seconds and then go straight to OC. This is also not a Cummins/Onan generator. It is made by Kohler.

[Viper]

Low voltage isn't always a direct result of battery condition, it could be a poor connection somewhere in the source or control wiring causing a voltage drop. This could be anything from corroded connections, loose connections, pulled out pins or broken retainers in harness plugs, etc. I would first check all connections made at components, harness plugs, switches, etc.

[hgauntt]

My Kohler 6.5 esz performed beautifully for more than 2hrs while cruising. Back in the slip i plugged in shore power and switched from ship to shore. The generator shut down on it's own. The generator will start but will not keep running when i release start switch. Oil level is good, conttoller fuse is good, breakers appear to be good.

I haven't removed oil pressure switch.

Any ideas?

[hgauntt]

Additionally when the engine is running with the dwitch held the gages inside do not show a voltage.

[Viper]

Switch to "ship", turn on a load like the hot water heater and try firing her up.