Generator shutdown solenoid tracking

[Ryan Wright]

Folks,

Something is causing my generator shutdown solenoid to shut down the
engine. Based on forum input and my own testing, I replaced the
voltage regulator to the tune of $200 and no change. Well, now I have
a spare voltage regulator.

So - How can I tell exactly WHAT is causing the solenoid to release?
At this point I suspect a bad oil pressure sensor since the oil
pressure shows really, really high, near 90psi and it never did that
before, but I'd like to be sure before I go throwing more parts at the
problem.

Kohler 12.5kw genset on Yanmar engine.

-Ryan
'86 PT-40 8V92
Tri-Cities, WA

[Ryan Wright]

Thanks to all for the excellent advice on my genset. I'm still SOL
here, unfortunately, however I think I'm on to something and I wanted
some advice:

Per the control system schematic, it appears the overtemp sensor and
the low oil pressure sensor will short to ground if there is a
problem, triggering shutdown. Indeed, I suspect this may be happening,
as my oil pressure gauge reads between 90-120psi. I tested the temp
sensor and there is no path to ground from it's contacts. However,
both of the oil pressure sensors (at least I think both of those
things I found on the engine are oil pressure sensors - I suspect one
goes to the gauge and the other goes to the control unit?) are shorted
to ground. Not the wiring leading from the sensors, but the sensor
terminals themselves.

Does this indicate a faulty oil pressure sensor? Should I replace
them? Is it possible they both went bad?! Unfortunately, nobody around
here wants to look at my generator and I'm not in a position to take
the coach across the state to have the nearest Kohler service center
check it out. Especially not in 100 degree heat, with no generator. So
I'm mostly guessing here and going on what little knowledge I can
gather.

Bob Loomas suggested I check the slip rings and brushes - I've not
done that yet. I have replaced the voltage regulator, didn't help.
Fuel cutoff solenoid wiring appears to be fine and intact, it opens
like it should upon start, just releases immediately afterwards. All
fuses appear intact. I'm not getting any power out of the generator,
though I can keep the engine running by holding the cutoff solenoid
open, I still get zero power output. I don't know if the control
circuitry cuts power output when it triggers the solenoid or not.

-Ryan
'86 PT-40 8V92
Tri-Cities, WA

[Ryan Wright]

Folks,

Thanks for all of the help on the generator. I believe I have found
the problem. There's a little white box with a couple of terminals, I
believe these are the brushes. One of the wires leading to a brush was
simply hanging, looks like it became desoldered. I'm going to call my
Kohler supplier Monday and order a new one. I'm betting that fixes the
problem.

So now I have a spare voltage regulator! I'll just keep it on board
as I'm sure mine will fail some day. Anyway, I'm learning a lot about
this generator. I sat there and stared at the back of the unit for
what seemed like 10-15 minutes trying to find these "brushes and slip
rings" and could not see it. Didn't realize the rings were so large
nor the brushes so small. I think the saying "You learn something new
every day" is true.

-Ryan
'86 PT-40 8V92
Tri-Cities, WA


On 7/31/07, randydupree wrote:
> Ryan.
> simply unhook the oil sending units for a test.
> if it works fine replace the senders.
> Randy
> ----- Original Message -----
> From: Ryan Wright
> To: wanderlodge@yahoogroups.com ; WanderlodgeForum@yahoogroups.com
> Sent: Monday, July 30, 2007 11:58 PM
> Subject: Re: [wanderlodge] Re: Generator shutdown solenoid tracking
>
>
> Thanks to all for the excellent advice on my genset. I'm still SOL
> here, unfortunately, however I think I'm on to something and I wanted
> some advice:
>
> Per the control system schematic, it appears the overtemp sensor and
> the low oil pressure sensor will short to ground if there is a
> problem, triggering shutdown. Indeed, I suspect this may be happening,
> as my oil pressure gauge reads between 90-120psi. I tested the temp
> sensor and there is no path to ground from it's contacts. However,
> both of the oil pressure sensors (at least I think both of those
> things I found on the engine are oil pressure sensors - I suspect one
> goes to the gauge and the other goes to the control unit?) are shorted
> to ground. Not the wiring leading from the sensors, but the sensor
> terminals themselves.
>
> Does this indicate a faulty oil pressure sensor? Should I replace
> them? Is it possible they both went bad?! Unfortunately, nobody around
> here wants to look at my generator and I'm not in a position to take
> the coach across the state to have the nearest Kohler service center
> check it out. Especially not in 100 degree heat, with no generator. So
> I'm mostly guessing here and going on what little knowledge I can
> gather.
>
> Bob Loomas suggested I check the slip rings and brushes - I've not
> done that yet. I have replaced the voltage regulator, didn't help.
> Fuel cutoff solenoid wiring appears to be fine and intact, it opens
> like it should upon start, just releases immediately afterwards. All
> fuses appear intact. I'm not getting any power out of the generator,
> though I can keep the engine running by holding the cutoff solenoid
> open, I still get zero power output. I don't know if the control
> circuitry cuts power output when it triggers the solenoid or not.
>
> -Ryan
> '86 PT-40 8V92
> Tri-Cities, WA
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
>

[bloomas]

----- Original Message -----
From: Ryan Wright
To: wanderlodge@yahoogroups.com ; WanderlodgeForum@yahoogroups.com
Sent: Sunday, August 05, 2007 2:00 AM
Subject: [WanderlodgeForum] Re: Generator shutdown solenoid tracking
Ryan Glad you found the problem.
Bob Loomas 1985 PT 36


Folks,

Thanks for all of the help on the generator. I believe I have found
the problem. There's a little white box with a couple of terminals, I
believe these are the brushes. One of the wires leading to a brush was
simply hanging, looks like it became desoldered. I'm going to call my
Kohler supplier Monday and order a new one. I'm betting that fixes the
problem.

So now I have a spare voltage regulator! I'll just keep it on board
as I'm sure mine will fail some day. Anyway, I'm learning a lot about
this generator. I sat there and stared at the back of the unit for
what seemed like 10-15 minutes trying to find these "brushes and slip
rings" and could not see it. Didn't realize the rings were so large
nor the brushes so small. I think the saying "You learn something new
every day" is true.

-Ryan
'86 PT-40 8V92
Tri-Cities, WA

On 7/31/07, randydupree wrote:
> Ryan.
> simply unhook the oil sending units for a test.
> if it works fine replace the senders.
> Randy
> ----- Original Message -----
> From: Ryan Wright
> To: wanderlodge@yahoogroups.com ; WanderlodgeForum@yahoogroups.com
> Sent: Monday, July 30, 2007 11:58 PM
> Subject: Re: [wanderlodge] Re: Generator shutdown solenoid tracking
>
>
> Thanks to all for the excellent advice on my genset. I'm still SOL
> here, unfortunately, however I think I'm on to something and I wanted
> some advice:
>
> Per the control system schematic, it appears the overtemp sensor and
> the low oil pressure sensor will short to ground if there is a
> problem, triggering shutdown. Indeed, I suspect this may be happening,
> as my oil pressure gauge reads between 90-120psi. I tested the temp
> sensor and there is no path to ground from it's contacts. However,
> both of the oil pressure sensors (at least I think both of those
> things I found on the engine are oil pressure sensors - I suspect one
> goes to the gauge and the other goes to the control unit?) are shorted
> to ground. Not the wiring leading from the sensors, but the sensor
> terminals themselves.
>
> Does this indicate a faulty oil pressure sensor? Should I replace
> them? Is it possible they both went bad?! Unfortunately, nobody around
> here wants to look at my generator and I'm not in a position to take
> the coach across the state to have the nearest Kohler service center
> check it out. Especially not in 100 degree heat, with no generator. So
> I'm mostly guessing here and going on what little knowledge I can
> gather.
>
> Bob Loomas suggested I check the slip rings and brushes - I've not
> done that yet. I have replaced the voltage regulator, didn't help.
> Fuel cutoff solenoid wiring appears to be fine and intact, it opens
> like it should upon start, just releases immediately afterwards. All
> fuses appear intact. I'm not getting any power out of the generator,
> though I can keep the engine running by holding the cutoff solenoid
> open, I still get zero power output. I don't know if the control
> circuitry cuts power output when it triggers the solenoid or not.
>
> -Ryan
> '86 PT-40 8V92
> Tri-Cities, WA
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
>




[Non-text portions of this message have been removed]

[Ryan Wright]

On 8/5/07, bloomas wrote:
>
> Ryan Glad you found the problem.

Thanks Bob. I appreciate your advice in telling me to look at these.
I was hesitant to do so right away because I had no idea what they
looked like and I didn't know how I was going to tell whether they
were worn or not. Sure enough when I was under there I had to look at
the thing for a very long time to find them even though they were
right in front of my face! Bill Schreurs called me up the other night
and we had a nice conversation about the whole deal, he helped me fill
in the gaps and I was able to find them.

It's a good thing I'm used to laying underneath cars for hours at a
time. Getting under the coach to the point where I could really work
on this was a unique experience. With the generator slide out, I was
able to crawl under there, then sit up rather comfortably in the
cavity created by the generator's removal.

-Ryan
'86 PT-40 8V92
Tri-Cities, WA