I am trying to install some after market auto gages into my cavalier. I was thinking of installing a "T" fitting into the block where the factory sensor is, or trying to tap into the electrical circuit It is a 3 wire switch and it is just a light in the dash it does not monitor any oil gage for pressure, I also confirmed the ECM does not read actual oil PSI by using an OBD Plug, it just monitors the fact it has oil pressure. I am looking good wiring diagram to help explain the 3 wires in the oil psi circuit or of it is possible for a good location to put maybe the after market pressure sending unit into the block somewhere.

 

You can put a Tee where the current switch is and put both sending units in the same port. You need to connect the old one to keep the ECM from sending a no oil pressure signal.

 

Okay I thought that would have been my solution. I was just hoping to get lucky there doesn't seem to be a lot of room in that area of the block. Make it work. Will post with what it looks like.

 

You can use a combination of the tee and an elbow and nipples to gain room. Make sure you use a good thread sealer.