Oil pressure alarm is gone

[Juan]

Hi everyone:

My oil pressure alarm stopped working. Before, you could hear the alarm when the key was in the ignition position and also in the glow-position (in that case, the alarm had a lower pitch sound), and would stop once the engine starts. Now, the alarm is always gone.

I thought the buzzers were too old. I changed them with new 12v buzzers from Radio Shack but still nothing...I checked the wires behind the panel, they were all fine...The motor seems to be running fine...Oil level is fine...

Any ideas on what to do (or check?)

Thanks,

Juan

[Jim Hardesty]

Check the oil pressure sending unit.  Not sure where it's at on your engine.  Mine is just in front of the starter.  To check it pull the wire off, when you turn on the key the alarm will sound if all else is OK.
Jim

[Ron Hill]

Juan : Your M25XP oil pressure switch is on the port side of the engine just above the starter solenoid.  Do the check that Jim suggested and if inop. then go to your Kubota tractor store and get a single pole oil pressure switch. 
Maybe just the wire/connector is broken or the screw backed out??

I wrote a couple of Mainsheet articles on that oil switch and WiKi has a bunch of posts as well. 

A few thoughts

[KWKloeber]

Juan,

The switch may have gone bad, or the light blue harness wire to the switch is open, or the circuit board is bad.

If you ground the terminal on the sender/wire end (located above the starter and a bear to get to) the alarm should sound.  If not the alarm is probably bad - Seaward had a circuit board that powered both the temp (from the gauge sender) and oil alarms, but it's no longer available.  There's a dual (light/buzzer) alarm avail that both the oil pressure and newer temperature SWITCH, not gauge sender can be hooked to.  The thought is if it alarms, shut down no matter the cause -- and just ck the temp gauge to know which is alarming.

Note that there's a Wb Service Bulletin out on the correct socket to remove/install the oil sender without damaging it.

Note also that the oil switch is a normally closed contact, and is 1/8" british / JIS pipe thread, not 1/8" NPT.  It's available at Autozone, though I don't have the p/n. Maybe they can cross it to the Kubota p/n.  I extended mine out a couple inches so it clears the exhaust manifold (and added a tee and sender for a pressure gauge.)  If it is extended, it can be fashioned to either retain the JIS thread, or with NPT thread (so more readily common NPT oil pressure switches can be used.)


Ken