1994 Golf - Oil pressure light keeps coming on

Ok. My 94 golf i just bought about 4 days ago has a light that keeps coming on thats the oil pressure. Now it sais it can go off if you have low oil i checked it and thats not the problem. Then manual says contact dealership. Not something i wanna do. So anyone here know maybe what the problem is so i can do it myself. I have 131000 miles on it and its currently running synthetic oil ( 5w30 ) just changed about 3 days ago. And i just put in new spark plugs and a k&n drop in filter today.

Any help is much appreciated