Oil Pressure Light When Running (No Buzzer)

Just got my car it's MOT done today and after giving it a quick run on the road I've got it back in the garage so I can change it's oil and filter. I've not had any instances of the oil pressure light blinking when the engine has been running but after changing the filter and oil the light is constantly blinking but without the warning buzzer. So far I've filled the car with 3L of oil and the dipstick is showing it as bang on the mark. I've pulled the oil pressure switch off the right side of the head so far to inspect it for contamination but I've noticed a rouge wire along side the wiring for the switch. It appears to be a earth but as far as I'm aware the pressure switch should only have a single wire. Does anyone have any idea why I'm getting this light now?  Any ideas if it's it the dipstick lying too me, the switch or something worse?

Did you fill the oil filter with oil before fitting it on?
If not unscrew it and pour some oil in it then refit it, you may get some oil coming out so have a cloth handy.
What make of oil filter did you use?

I did fill it with oil before putting it on but I'll take it back off and try again. Filter is a Mann. Ordered a new pressure switch which I'll fit first. The one on was the original by the look of things and was oily on the outside. Still shouldn't be that though as it was running fine before the oil and filter change.

I've had the same problem twice after an oil change but I've got hydro tappets and they was noisy on start up and light flashing so I knew oil was not getting around the engine, 1st time I fitted another new oil filter and 2nd time I put more oil in the filter and that seemed to solve the problem. Not had the problem for a couple of years.

mark1gls said

I've had the same problem twice after an oil change but I've got hydro tappets and they was noisy on start up and light flashing so I knew oil was not getting around the engine, 1st time I fitted another new oil filter and 2nd time I put more oil in the filter and that seemed to solve the problem. Not had the problem for a couple of years.

Fixed. Was a filter on filter off job. Cheers for the help.

No worries, glad it was a simple fix.