I've had a look at some old posts but they aren't very conclusive imo, so I'd like to ask, from those of you that know exactly what each of these are and what they do/control. With all due respect, pls don't comment if you don't know 200% that you're correct as apparently its different year to year so I need it to be correct info pertaining only to an 88 305TPI. Sorry the pics are a bit grainy, they're screenshots of someone's pics in an old post...



I have both of these oil pressure senders/switch/ sensors.
​1988 TransAm, 305TPI, all stock and factory original and has both of these, the bell looking one behind the block attached to an elbow and the other one down next to the oil filter.

What exactly does each of these do or control ?

Thanks guys.

 

Picture number 1 is for the dash gauge
picture 2 is the ops but they do have a all in one that’s 3 wire that works a gauge or idiot light
and fuel pump.

 

Thanks man, appreciate the clarification.

What are symptoms of both of these parts when failing or failed?

 

The oil pressure switch is backup for the fuel pump relay.
failure the fuel pump won’t run after 4 psi of oil pressure is built.
a bad sender the number 1 gauge will not work or idiot light won’t work.
or both can leak being a failure.

 

What would cause the gauge needle to bounce around at idle, not too much, like just under 30, then 30, then just over 30, then back down to 30 etc.. has a new sender but would do it before too...

 

Poor connection somewhere, or ground.

 

Holy geriatrics, Batman! Look who's still around.