Which oil pressure sensor?

[vilant]

My oil pressure gauge is all over from 0-80psi. Looked through solutions and parts list and I'm confused as to which sensor controls the gauge on the instrument panel. Is it AC delco # D1846(single pin), which is located on the right side of engine underneath oil filter by oil cooler hoses? Or is it AC delco # D1808a(three pin), which is located right next to oil filter, accessible from top of engine? Bought the single pin sensor, but now I'm not sure if I bought the right one as the 3-pin sensor looks like it has a coating of oil on it. Any help would be appreciated