520-H Oil Pressure Switch

[Horse Newbie 6,853]

I have a little problem with my 520h that I need some info on before I move forward with any possible repairs and/ or fixes.

It looks like previous owner wired the two wires going to the oil pressure switch together with a wire nut. ( I would have at least used a butt connector, but then again I probably would not do it to begin with).

Why would he do that ?

Can anybody give me a clue ?

I will confirm the wire colors tomorrow. But for now, I need some general info. on the 520h oil pressure switch.

From what I understand the switch is "normally closed", and would open when you have a low oil pressure situation, causing a warning light to come on on the dash.

Is this correct ?

And the switch is not a "kill switch".

Is this correct ? 

Why does it have two wires ?

I figured one power wire and ground to the block.

Any suggestions on where to get one ?...part number ?...

[lynnmor 6,762]

One wire turns off the oil pressure light when the engine starts.  The other wire provides a ground to the hour meter so it only runs when there is oil pressure. 

[Horse Newbie 6,853]

Would you get a switch from Onanparts, or Ebay/ Amazon ?

[Horse Newbie 6,853]

1 minute ago, Horse Newbie said:

Would you get a switch from Onanparts, or Ebay/ Amazon ?

 

18 minutes ago, lynnmor said:

One wire turns off the oil pressure light when the engine starts.  The other wire provides a ground to the hour meter so it only runs when there is oil pressure. 

 

[richmondred01 2,202]

There were two types of oil pressure sensors used.

Both can be tested using a multimeter and a few pounds of air pressure from an air compressor.

The prior owner most likely by passed the sensor to get the light to stop blinking. 
You can also use the mounting hole where the sensor was to install an oil pressure gauge rather then the light. 

Edited September 28, 2020 by richmondred01

[lynnmor 6,762]

6 hours ago, Horse Newbie said:

Would you get a switch from Onanparts, or Ebay/ Amazon ?

Don't hold me to this, but I believe that this switch will work if you run a ground wire to the common terminal.  Look up the part number (1S6552) for alternate sources.

Here is a list of oil pressure switches and their specifications. 

 

[Horse Newbie 6,853]

Thanks a lot for the help ! So I would use terminal 2 and ground ?

[richmondred01 2,202]

You should use the oil pressure switch that was designed for that model.

Your old switch has a part number on it. Look up that part number and get that part or a superseded correct one. This information can be gleaned via several onan websites or a Cummings dealer. 

[Horse Newbie 6,853]

I don't have the old switch...previous owner took it out and installed a plug in its place, and just wired the two wires together with a wire nut ...smh

Edited October 11, 2020 by Horse Newbie
Misspelling

[richmondred01 2,202]

Does the engine have its identification plate on the blower housing?

That spec information, along with the toro model number, found under the seat, will be needed to pinpoint the correct switch. 

 

Edited September 30, 2020 by richmondred01

[lynnmor 6,762]

10 hours ago, Horse Newbie said:

Thanks a lot for the help ! So I would use terminal 2 and ground ?

The switch I linked to has 3 terminals instead of 2 like the OEM switch.  One of the 3 terminals is the common that should have a wire connected and run to a ground on the engine.  The OEM switch uses the mounting threads as the ground.  There is no fear of using the "wrong" switch, the worst that can happen is the oil light will not work, but then you will know that the switch needs to be connected properly.  Another number for the same switch is PS119, available at most auto parts stores.

[Horse Newbie 6,853]

Thank you...I will update my progress as soon as I can. I really appreciate the responses.

[Horse Newbie 6,853]

2 hours ago, richmondred01 said:

Does the engine have its identification plate on the blower housing?

That spec information, along with the toro model number, found under the seat, will be needed to pinpoint the correct switch. 

 

Yes it does have the plate. I have recorded that information in case the plate fades or gets damaged so I wouldn't be able to read it.

[Horse Newbie 6,853]

On 9/27/2020 at 10:10 PM, lynnmor said:

One wire turns off the oil pressure light when the engine starts.  The other wire provides a ground to the hour meter so it only runs when there is oil pressure. 

Which color wire goes to which terminal ?

[lynnmor 6,762]

Turn on the switch and ground a wire, if the oil pressure light comes on, that wire goes to the terminal that turns on the light.

Edited October 9, 2020 by lynnmor
Said it wrong

[Horse Newbie 6,853]

2 hours ago, lynnmor said:

Turn on the switch and ground a wire, if the oil pressure light comes on, that wire goes to the terminal that turns on the light.

Thanks lynnmor...i am just collecting parts, fuel line, fuel filter, spark plugs, coil, just things I know need to be addressed before I attempt to start her up and test her out.

I bought the 520h a few years ago, had a carb problem, cleaned her a little and put her in the stable.

Now I have decided to clean her good, do some basic maintenance, and see what she'll do.

 

I really appreciate the advice !

[Horse Newbie 6,853]

On 9/27/2020 at 10:10 PM, lynnmor said:

One wire turns off the oil pressure light when the engine starts.  The other wire provides a ground to the hour meter so it only runs when there is oil pressure. 

I have a question... Sorry but it is on a different topic, but still kinda related. What oil filter do I need ( WIX or NAPA ) for my 520H/ Onan P220G engine. I plan on putting SAE 30 wt. oil in it as I will not be operating it at temps below 32 degrees. I apologize for flipping the topic, but I was having a little trouble navigating Red Square on my phone.

[lynnmor 6,762]

I use Onan 122-0800 or Fleetguard  LF3339, they are the same and you can even find green Onan boxes containing the white Fleetguard filters.  Some filters have no flutes for an oil filter socket to grab, just one reason that I stay with the Cummins products.  Shop by part number, you can find prices that vary widely.  I use SAE 30 year round, the tractors for snow removal are kept in a heated garage nearly all the time.  Be aware that most SAE 30 has been given a SN rating giving them less wear resistance than in the past, I switched to Kohler  part #25 357 02-S oil for that reason.

[Horse Newbie 6,853]

4 hours ago, lynnmor said:

I use Onan 122-0800 or Fleetguard  LF3339, they are the same and you can even find green Onan boxes containing the white Fleetguard filters.  Some filters have no flutes for an oil filter socket to grab, just one reason that I stay with the Cummins products.  Shop by part number, you can find prices that vary widely.  I use SAE 30 year round, the tractors for snow removal are kept in a heated garage nearly all the time.  Be aware that most SAE 30 has been given a SN rating giving them less wear resistance than in the past, I switched to Kohler  part #25 357 02-S oil for that reason.

What filter and oil do you use in the Hydro ?

[lynnmor 6,762]

I use the Wix 51410 or Napa 1410 oil filter and Castrol 03110 GTX High Mileage 10W-30 Synthetic Blend Motor Oil.  When I switched to the synthetic blend from conventional oil, there was a noticeable difference in response.

[Horse Newbie 6,853]

8 hours ago, lynnmor said:

I use the Wix 51410 or Napa 1410 oil filter and Castrol 03110 GTX High Mileage 10W-30 Synthetic Blend Motor Oil.  When I switched to the synthetic blend from conventional oil, there was a noticeable difference in response.

Alright, thanks. I appreciate it. 

Does the Eaton 100 trans. have a vent hole ?... because I noticed as I'm filling it up I am getting a burp through the filler tube and it is backing up.

[richmondred01 2,202]

2 minutes ago, Horse Newbie said:

Alright, thanks. I appreciate it. 

Does the Eaton 100 trans. have a vent hole ?... because I noticed as I'm filling it up I am getting a burp through the filler tube and it is backing up.

Remove one of the two bolts that holds the seat/gas tank bracket.

That will allow you to vent. 
clean the area prior to removing the bolt so dirt doesn’t get into the transmission.

[Horse Newbie 6,853]

6 hours ago, richmondred01 said:

Remove one of the two bolts that holds the seat/gas tank bracket.

That will allow you to vent. 
clean the area prior to removing the bolt so dirt doesn’t get into the transmission.

So the trans. case does not have a vent itself ? I was going to make sure that it wasn't maybe blocked with debri...sounds like it does not have a vent.

Edited October 11, 2020 by Horse Newbie

[lynnmor 6,762]

9 minutes ago, Horse Newbie said:

So the trans. case does not have a vent itself ? I was goi g to make sure that it wasn't maybe blocked with debri...sounds like it does not have a vent.

I don't remove the bolt because of the risk of dirt getting in, I just take my time and let it burp away.  The vent is the dipstick, the curled end is hollow and often smashed shut or blocked with debris, so check that.  It won't help with the indigestion, but it will help with preventing pressure when temperature changes.

[Horse Newbie 6,853]

30 minutes ago, lynnmor said:

I don't remove the bolt because of the risk of dirt getting in, I just take my time and let it burp away.  The vent is the dipstick, the curled end is hollow and often smashed shut or blocked with debris, so check that.  It won't help with the indigestion, but it will help with preventing pressure when temperature changes.

I read where the Eaton 1100 holds about five quarts of oil. Will this be true if I drained it completely at the drain screw ? What I'm thinking is get it to the full mark , let the pump run maybe a minute or two, to let the air maybe work its way to a point where it will vent, and the filter fill up, and recheck level...sound good ?