Kohler 150kw coolant low fault - HELP

electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
Occupation
Electrician
Hey guys , long shot here but I've got a Kohler 150 that's saying coolant level low and shutting the generator down. The generator is very new. Coolant level is at the top of the sight glass. Of course as Murphy's law states , we have a power outage this morning and the damn thing won't run. Looking for at least a quick fix. I tried jumping out the coolant level sensor but still no go, not sure if there's another one, or it's looking for a specific resistance. I clear the fault but it comes on again after a short time. Any ideas? God I hate generators.
 
Do you need a manual. I just had kohler send me for there industrial from 20-2250kw gen. I am sure that covers yours.
It’s like 300 pages so I have not dived into it.
 
AC\DC said:
Do you need a manual. I just had kohler send me for there industrial from 20-2250kw gen. I am sure that covers yours.
It’s like 300 pages so I have not dived into it.
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Yeah we have the literature, that's the next step is to dive into the wiring diagram and trace that sensor wire back. It's just a two wire sensor, so shorting it should make it run, must be a break somewhere else. Theres a YouTube video of a guy with a different Kohler, but the problem was at the pin where it plugs into the controller. Did i say I hate generators?
 
UPDATE: We have generator power. Got a tech from the local generator place to come. He brought a new sensor, said those things go bad frequently. He goes to put it in and it doesnt fit 🙃 . End up doing a cob job with the thing sticking in a tube of water for now, but its working.. City Light is pumping out and looking in vaults trying to find whats wrong......still curious about the resistance profile of that sensor, will take some readings when the dust settles.
 
Birken Vogt said:
Several sensors were used over the years. Is this the large black plastic one with white sticker or one of the brass ones?
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I am not sure what it looked like, my guy was there not me. He wasn't able to satisfy my curiosity and get a resistance measurement as the generator was still running when he left. But I'll check at one of these days and get back to y'all on it.
 
This seems strange to me.

Because the common old level sensor used from about 1985 to 2015 was a brass one with a red and black wire. Black was ground and red was low resistance to ground when the level went low. When the level was full then red was mostly open circuit. You could bypass it by simply disconnecting the red.

The more current one is a larger plastic hockey puck, but I have never metered it, but it must work similar. I have one right now at a customer that has apparently failed, we have disconnected it and it runs fine without it. The only other failure of one I saw was when some hippy hooked 120 volts to the 12vdc battery bus.
 
I have no idea what they use but I could see it being a rather simple conductivity probe of some sort if all it is doing is detecting whether there is liquid present at the probe location. It would likely detect conductivity between probe and engine block through the coolant.
 
Update: So everything worked fine, SCL got power on late afternoon Friday. But guess what happened again sometime early this morning (Sunday)? power back out., been out all day, current estimate is 3 AM. Generator is running fortunately. Anyone know some good lineman that they can send to fix this since SCL apparently cant get it fixed, this is like the 12th time in 2-3 years this section of UG goes down. Love the outage map, SCL giving us the finger.....Also looks like something else......
 

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electrofelon said:
I tried jumping out the coolant level sensor
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Most automotive systems the coolant sensor, if a switch, closes between two contacts, or grounds to the threaded metal part, so disconnecting it makes the circuit see normal temperature.

If a variable resistance or more modern voltage output (three wires needed) then could be either way. I would have tried open first, pulling the connector off.
 
Frank DuVal said:
Most automotive systems the coolant sensor, if a switch, closes between two contacts, or grounds to the threaded metal part, so disconnecting it makes the circuit see normal temperature.

If a variable resistance or more modern voltage output (three wires needed) then could be either way. I would have tried open first, pulling the connector off.
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Yeah neither open nor closed circuit did it. Maybe they measure resistance to ground/case of radiator, but if that was the case doesn't seem like they would use two wires to the sensor.
 
Birken Vogt said:
The ones used as long as they had brass radiators had some kind of magic inside. They were high resistance when immersed in coolant, almost open circuit, and resistance dropped quite low when in the open air.
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Other way around would make sense if it were a nothing more than a conductivity sensing probe. Which possibly would be my choice of how to sense low level if I were the one making decisions on the design. Seems would be more fail safe as well because you basically get a low level signal if leads to your probe have open circuit condition. If sensing from a single probe to "ground" however a shorted probe lead gives you a false signal that the level is fine.
 
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