Recently acquired a 96 Case 1818 Uni Loader Skid Steer (533 hours). Shortly after purchase had to replace battery (10 years old so was time). On restart getting oil pressure warning light and alarm. Checked oil level and was fine (been changed approximately 50 hours ago) Changed oil and filter but no change in status of light and alarm. Checked oil pressure using the fitting at the remote oil filter for the oil temperature probe and measured 32 PSI at idle and over 45 at mid throttle position. Was also seeing a battery light and did the shop manual trouble shooting on this and suggested the problem here was a bad voltage sensor, however, after running the skid steer for about 10 minutes this light went out. I suspect I may have a bad oil pressure sensor. I have two questions: First as these are NLA from Case does anyone have a known aftermarket sensor that will work? Second, it looks like the sensor is mounted to a plate on the left side of the Onan engine. Is this sensor accessible without removing the engine? Any advice or help much appreciated.