MEP 803A won’t start - high temp warning light

[pclausen]

Have a 803a that normally runs just fine. Tried to fire it up this morning due to power outage but it won’t crank. I get the high temp warning fault LED in the run position. Batteries fully charged. Cranks fine via dead crank switch. In run/aux position I hear the aux fuel pump, but in regular run mode I don’t hear the main fuel pump. Did a fault reset, but high temp fault comes back as soon as I move S1 to run position.

With no power and still dark outside, I’m not able to look at my manuals pdf file stored on my computer.

Any quick checks or bypasses I can do to get this thing going to power the house?

 

[pclausen]

If I flip the battle short switch on, I do hear the main fuel pump in prime & run, but it still won’t crank.

 

[pclausen]

Disconnected high temp sensor got it going. Guess that failed for some reason?

 

[Farmitall]

Have a 803a that normally runs just fine. Tried to fire it up this morning due to power outage but it won’t crank. I get the high temp warning fault LED in the run position. Batteries fully charged. Cranks fine via dead crank switch. In run/aux position I hear the aux fuel pump, but in regular run mode I don’t hear the main fuel pump. Did a fault reset, but high temp fault comes back as soon as I move S1 to run position.

With no power and still dark outside, I’m not able to look at my manuals pdf file stored on my computer.

Any quick checks or bypasses I can do to get this thing going to power the house?

As highlighted above.......this the great reason why having a paper manual (or at least some excerpts) ready at hand is a very good thing to have.

Glad you got the set going.

 

[Light in the Dark]

Yes the sensor has likely failed. Battle short in a pinch, or just make a real quick double male end cable and hook the leads together.

 

[pclausen]

^^ For some reason disconnecting the coolant switch wires and leaving them open circuit made the high temp warning LED go away. I too would have thought the temp sensor would be short circuit when temp was ok and open up when too high. Guess its the other way around.

@Farmitall Definitely a good reason to keep a set of paper manuals around!

 

[Guyfang]

1. Remove coolant high temperature switch
2. Suspend coolant high temperature switch in a container of 50/50 mixture of antifreeze and water so that sensing element is completely immersed but not touching sides or bottom of container.
3. Suspend a reliable thermometer in container. Do not allow end of thermometer to rest on bottom of container.
4. Set multimeter for ohms and connect between coolant high temperature switch terminals. Multimeter should indicate open circuit.
5. Gradually heat antifreeze/water mixture, stirring so that heat will be evenly distributed and observe thermometer
and multimeter.
6. At between 220 and 230 °F (105 and 110 °C), multimeter should indicate continuity.
7. Replace coolant high temperature switch if it fails to operate as above.
8. If replacement is not needed, install coolant high temperature switch.

Or, using your multimeter, measure the Continuity of the Over temp switch, as is, cold, in the engine block. If the contacts are closed. Its bad. If its open, THEN I might perform the test as stated above.

 

[Light in the Dark]

^^ For some reason disconnecting the coolant switch wires and leaving them open circuit made the high temp warning LED go away. I too would have thought the temp sensor would be short circuit when temp was ok and open up when too high. Guess its the other way around.

@Farmitall Definitely a good reason to keep a set of paper manuals around!

You are right, its a normally open contact switch. Been a few years since I have had to swap one out. Its one item that rarely goes bad, but does happen.

 

[kloppk]

Or PDF copies on your phone

 

[pclausen]

Thanks @Guyfang exactly what I was looking for.

803A still humming along powering the house with the coolant temp holding steading right around 180F per the gauge. I thought I had an extra coolant high temperature switch on my parts 802A, but I guess I already used it on another set.

Anyone got a spare temp switch they want to get rid of?

The 803A is parked in my shop extension, connected to a manual 100A transfer switch, which in turn is connected to a 400A automatic transfer switch that powers both the house and the shop.



My primary backup generator is a 20 kW Kubota that I'm currently working on:



Should be getting the last few parts for it in this week.

Back wall of shop where power comes in and then runs up to the house. From left to right: 400A meter base, 400A fused disconnect, 400A transfer switch, junction box (gutted 400A meter base):



The box on the far right at a 45 degree angle is my 225A solar sub panel.

You can never be too prepared for a power outage!

 

[Light in the Dark]

I know you dont need 5 of them, but only place I see them for sale new right now: https://www.ebay.com/itm/124183942354

I may have one on a spare 802 engine I have, untested.

What model Kubota?

 

[Light in the Dark]

Or PDF copies on your phone

You will catch me eating soup with my cell phone, before you catch me trying to view a PDF on it.

 

[pclausen]

@Light in the Dark Thanks for the link. Yeah, I definitely don't need 5 of them though. Sent you a pm.

Kubota engine is a V2003T (2.0 liter turbo) with a rated output of 30.6kW @ 1,800 rpm. The gen head is a Mecc Alte 20kW. I added a DSE 7410 MKII controller which has an ethernet port so that I could fully automate when the generator comes on, does its weekly exercises and monitor the engine and generator from anywhere.