Hi all.

After going back and forth to my local regular mechanic and then main dealer, I've been trying to find out about my oil pressure light problem with little result, so I've joined this forum as a new member to see if anyone can shed any light.

I have a 2010 Grand Voyager 2.8 diesel that's covered about 42000 miles. When I start it from cold the warning light does not come on during idle but will illuminate at around 1500-2000RPM when I start driving (or 2000RPM in neutral). The light will go on and off at various stages during a journey but then stops once up to normal running temperature.

So far local mechanics have changed the oil pressure switch twice and were then reluctant to help again, suggesting I go to main dealer.
Main dealer checked oil pressure and said they had found some bare wiring which they taped up, changed a brake light bulb to road test and then charged me handsomely for.

This did not rectify the problem, as when I started from cold again the light came on at the higher RPM's again.

Can anyone suggest any possible causes please?
Many thanks in advance.