No idea 1 #1 Posted September 23, 2016 I have a wheel horse 520hydro and I'm having a problem with with what I am assuming is the oil pressure switch. The tractor will fire up and run great for a few minutes then suddenly shut off and have no spark, the oil pressure light blinks on the dash but I have checked the pressure and it's fine. Is there anyway to bypass the switch? Because the dealer is telling me the oil pressure switch is on backorder and or discontinued Share this post Link to post Share on other sites
953 nut 60,224 #2 Posted September 23, 2016 You didn't mention the year so I just picked a manual at random. I believe the oil pressure switch goes to ground on a lack of oil pressure which shorts the magneto and kills the ignition. If you remove the wire from the switch it should let the engine run. Chances are there is an automotive pressure switch that will do the job, just a matter of finding a good parts man who cares enough to look it up. 2 Share this post Link to post Share on other sites
No idea 1 #3 Posted September 24, 2016 I wish I knew the year but I'm not really sure I know the part number for the oil pressure switch is NN10273 I want to say it's a mid 90's tractor. I did disconnect the wires from the sensor and the tractor still died maybe I'm looking in the wrong place? Share this post Link to post Share on other sites
benji756 341 #4 Posted September 24, 2016 to red square, if you have a floor shifter its a 1988 or 1989 you should be able to use the model number to check it out. Are you sure its not running out of gas and stalling? 1 Share this post Link to post Share on other sites
No idea 1 #5 Posted September 24, 2016 I did check the fuel twice just to be sure, it just completely loses Spark, if I let it sit for a period Of time it will fire right back up again Share this post Link to post Share on other sites
benji756 341 #6 Posted September 24, 2016 sounds like something is heating up causing this problem, I'm sure someone with more knowledge than me will be along to help soon. Share this post Link to post Share on other sites
cleat 7,263 #7 Posted September 24, 2016 Sounds like the ignition module is going out. Module is located behind the flywheel. My 520HC was doing the exact same thing and a new module fixed it up. 1 Share this post Link to post Share on other sites
953 nut 60,224 #8 Posted September 24, 2016 10 hours ago, No idea said: wish I knew the year but I'm not really sure There is a sticker under your seat that has a model number on it, use this chart to find the year based on model number. wheelhorseallyears.pdf Your opening question was regarding the oil pressure switch, who told you this was the problem? 1 Share this post Link to post Share on other sites
No idea 1 #9 Posted September 24, 2016 I just assumed it was the oil switch because of the oil light blinking... It's a 97 Share this post Link to post Share on other sites
953 nut 60,224 #10 Posted September 24, 2016 Here is the proper manual for your 520. Looking at the wiring diagram I see that you have what is referred to as a battery ignition system (requires 12 volts to operate). You will see a component called the "Kill switch" with a yellow wire from it going to the engine connector and on to the ignition module. @cleat suspects it may be the ignition module; lets test that theory. Locate the yellow wire at either end and put a DC volt meter set to 20/25 volts DC, red lead to the wire and black lead grounded well. Put a timing light or other type of spark tester on a plug wire to monitor the ignition spark condition. When the engine is running you will have 12 volts +/- on the yellow wire and if you continue to read 12 volts after the engine stalls out but there is no spark then you can be rather sure it is the module. 1 Share this post Link to post Share on other sites
No idea 1 #11 Posted September 24, 2016 I'll give that a try! Thank you 1 Share this post Link to post Share on other sites
WNYPCRepair 1,923 #12 Posted September 25, 2016 6 hours ago, No idea said: I just assumed it was the oil switch because of the oil light blinking... It's a 97 The oil light blinks until the engine spins and the oil pump builds up pressure. 1 Share this post Link to post Share on other sites
