Oil Pressure switch

[Grant Hayden]

 My oil pressure fluctuated the other day, from about 50-75, Not sure if this is normal. I never noticed this before, it was when the engine was cold. My mechanic is currently doing a service and wanted to test the oil pressure switch, but can not seem to find it on my C-9. He knows there is one for the ECM, but indicated there should be a separate switch for the dash guage. both the alladin and dash gauge indicated the fluctuation in pressure, Where might the pressure switch be located on the C-9 Engine?
Thanks
Grant

[Jim Nichols]

Under the intake manifold midway back. Tough to get your eyes on it so use a mirror .

[Grant Hayden]

Jim, Thanks.  As stated above, the oil pressure goes over 100 when cold, but drops quickly when the engine gets warm to about 45 -50 when cruising. From all I have read this is normal and nothing to worry about. We are departing for Florida in a week and I want to have a good trip.
Thanks

[Bill Dowell]

Ok .. Following this thread.. Where is the other Oil pressure sender for the ECM.. I have a strange behavior on my C9..after I had dealer service and now  I have a temporary drop of the oil pressure on the Aladdin display to zero while the dash remains at exactly where it belongs!!  After a minute or less.. the Aladdin returns to the correct value as well and remains normal from that point on! Of course the dash check engine light flashes and all that .. but I am sure the pressure is ok from the other dash gauge !  IDEAS ? and location of separate sensor ?

[Dave Atherton]

Bill, maybe I can answer the question you are asking. The Aladdin get it information from
data cable from the caterpillar engine in back to all your gauges on the dash and is tied into
This data cable. Dave has ran into several different readings with the Aladdin such as your
talking about. Connection of Cat ET reading your engine information finding that problem is
within your Aladdin and again not with the Cat engine. Not pushing other brands but have
But to my understanding that Aladdin is no longer can be serviced and issues are starting
to stand out. Dave Atherton Retired Cat Mechanic

[Larry Moore]

Bill

We had the same issue, there are two separate oil pressure senders on the C-9. The one that feed the Cat ECM was not always reading correctly, we replaced it and now the dash gauges and the Aladdin report the same values.