Problem with Oil Pressure sender/guage for 350 Cummins ISC

[Darrell Terry]

Engine oil pressure on our 350 Cummins ISC was always 75 lbs pressure.
On trip to Oregon - My oil pressure gauge read - with engine "off" 30 PSI.
When engine running it rises to 125 PSI.

Asked Cummins in Coberg to check it out during May oil change and road check.
Cummins replaced the oil pressue sender that Monaco installs adjacent to oil filter.
My oil pressure guage is now fully deflected to right - no movement at all - pegged to far right of gauge.
Cummins told me they must have installed wrong OHM sender but did not know what sender was needed. 

I have researched internet and found that I needed a 0-100 PSI sender with 33 -240 ohms.
I purchased a Datcon pressure sender from Amazon with those exact spec's.

Nothing - The gauge is still pegged to full deflection and no movement with or without the wire connected.

Do you think Cummins damaged my gauge with an incorrect sender or something else ?

Any help appreciated

[Eric Maclean]

Darrell
Try taping on the gauge face it may be stuck pegged.
It should at very least go full gauge when disconnect and full opposite if the wire is grounded.
 
Sending units can be either increasing resistance as pressure increases or decreasing resistance as the pressure increases
You may have the wrong sending unit.