Check the wiring to the oil pressure switchs ,blue one ? yellow one ? where the wiring runs by the rad fan
I got 2 switchs for about £15.00, but my switchs where ok
I had a similar problem when I got my kr.did a oil pressure test and it was good .
I just replaced both pressure switches and the problem disappeared.
Not sure if your part numbers are correct but mine had a white switch and a blue/brown switch also.