Well, I can tell you where it is on a 308, maybe it is the same on your 3.2 liter.
If you stand on the driver's side of the engine, look at the oil filter, now look down at the oil filter mounting housing. You will see a fairly decent sized fitting with a wire coming out of it. That's not it. That is the oil pressure switch that runs the light to tell you when you have NO oil pressure. Now lean over the oil filter and look at the oil filter base (on the intake manifold side), you will see a smaller fitting with a wire attached to it. That's the oil pressure sending unit that powers the gauge. You do have to remove the oil filter base to change the sending unit (at least on a 308).
Hope that helps!