Does any one know why there are two switches for the oil pressure? They are both located on the oil filter housing assembly. The upper switch on my son's 88 Fbird was leaking and the gauge was inop. It was not leaking alot, but enough to be coming out the "cannon" plug connector. When I pulled the old unit, it was stamped "vent".

Is this a pressure differential system?

I went to the parts store and they only had pressure switches labeled "pressure". After installation, the gauge is now functioning and I assume is accurate (higher pressure on cold oil, pressure lowers after warm and at idle, even lower when warm and in gear).

If any one can explain the system, I'd appreciate it.

 

That's easy.
The OTHER ITEM
is the
LOW OIL PRESSURE
ELECTRIC FUEL PUMP
Cut off switch.
Like, if car got hit, engine dies, cuts off fuel pump in tank, to stop, the obvious.

 

Hi Carl, this is a common misconception. After all these years of hot-rodders putting in oil pressure cutoff switches I even thought the same thing.

The switch is actually there to make sure the pump is running whenever there is oil pressure. GM did this to ensure a running fuel pump in case of relay or ECM failure.

RBob.

 

THANKS FOR THE CORRECTION.
I see I had the correct idea, but, phrased wrong.
Tip of my hat!