a mechanical oil pressure gauge will have a plastic or metal tube runnin from that location to the aftermarket gauge in cockpit. the factory guauges that run off the elctrical system are known to have problems due to voltage concerning the oil gauge ( known by some as idiot light!) . some people don't like adding the mechanical gauge package but it will tell the actual oil pressure, temp reading, and voltage. most will agree it is a good thing to have, easily removed if you ever sell it to a " mopar purist!!". hope this helps.
