What is this sensor??

[MichiganLarry]

We are doing the proverbial 4wd swap on my sons truck. When we pulled his engine from his 2.9 there was a wire going to a sensor on the side of his oil pan. The engine from the 88 donor 2.9 didn't have one. What is this for?

 

[Explorin94]

Oil level sensor. It lights up when the oil get low in the pan...if the engine does use oil.

 

[MichiganLarry]

Thanks. Had an idea that might be what it is.