Oil pressure light on at 25 psig

[FTBY55]

Have been having some issues with my '96 FatBoy. Oil light coming on once operating temp of 175 or more reached. Oil light comes on at idle or during acceleration. Pressure gauge is mounted above tappet screen and when shutdown reads 0, cold startup 40+, cruising warmed up at 25. When light comes on I am seeing 25 on the gauge. Have replaced sending unit and all springs, screens, checks and bearing ball. Followed sending unit wire9 green with yellow tracer back through connector all the way to lamp. No grounded points or chafed wires shorting out. If the sending unit is off the same feed port as the screen and gauge how is this discrepancy possible?

Any thoughts would be appreciated.   

[Burnout]

Cut open the oil filter and check for badness?

Are you using 20w-50 oil?

Try some 50w?

Test sender, are you using OEM?

[koko3052]

As Burnout says....but validate your gauge also.

[FTBY55]

Have checked and cleaned the K&P Oil filter. Was running Liqui Moly 10-60 last, now back to MOBIL1 V-Twin 20-50.
Just replaced the pressure switch with a new OEM unit. Also just replaced the Arlen Ness pressure gauge with new unit. Gauge reads and changes with oil temperature increase from idle to cruise.

Thanks