95 Trooper Oil Leak

I have an oil leak up front on my trooper. Seems to be coming from a hard line on the passenger side on the truck. This line passes under the radiator and then turns up and has a coupling that is near the alt, ac compressor area. Is this a cooler line? The oil filter area has a little oil on it, but the 2 sensor switches seem dry and I believe that area is getting wet from the above mentioned hard line drip. Any ideas why this line is leaking? O-ring maybe? Any help would be great. Thx