Can someone tell me specifically where the oil pressure switch is located on a 1987 760 turbo (B230FT) engine?

The other night my service engine light came on for the first time since I have owned the car. The car now has 220K and I have been driving it for 40K. I had just left work and I stopped and checked to make sure the oil level and such was OK. I started driving again and the light went out. I drove 40 miles before coming to a stop light where my oil pressure light began to flicker. As I pulled away the light went back out but then returned again shortly and became more persistent. It initially seemed to come on more solidly while going around corners. Now it is on most all of the time. I stopped driving the car of course. After reading some of the posts in this board it seems most likely I have a short in my electrical harness but I've already purchased a sending unit and would like to locate it and replace it first before getting into the harness.