Oil sending unit

[fredws]

I noticed my oil pressure gauge has started jumping up to 80 psi every so often, even without the engine running. So, I figure I need to replace the oil sending unit, but it looks like there are two there. One of them has two wires going to it, and the other is a larger, canister type, with one wire going to it. Which one do I need to replace, and what is the other one for?

[Slim]

the larger one will usually be the one the works your gauge ,,,and is a sending unit ,,,,,the other ,,the smaller one usually works yr oil idiot light and is just a sensor

[Terry B.]

Your sending unit will have just one wire going to it.

[Jeep Craze]

the smaller two wire on eis for the choke preheater, only energizes it when there is oil pressure in the system. At least thats the way it was on the MAC built ones. when chrysler took over dont know if that changed or not?