Oil pressure light

[ozitzmann@atmi.com]

I need some advice regarding the oil pressure symbol (light) on my '90 200 Avant
which flashes intermittently.  I have searched the archives and found no
solution.  The gauge reads good oil pressure and I have changed the single-wire
sender.  The problem is completely irregular:  sometimes it blinks when I first
start the car in the morning and stays on, other times it doesn't blink all day,
and still other times it goes on and off while driving, irrespective of RPM.  I
have tried heavier oils and I am using an OEM filter.

I suspect it's the wire or the computer, but I don't know where to start
looking.  Has anybody solved a similar problem, or simply disabled the oil
pressure symbol?

Thanks in advance,
Oliver