I am trying to run down my factory oil pressure gauge which isn't working. I was surprised to find battery voltage with "key on" at the sensor wire, should that be 12v or would it be coming from the dash regulator at ~6v?
How the regulator works is that current flowing thru it heats up a bimetallic strip that opens a set of contacts, the strip cools and the contacts close, etc, etc. averaging ~6v at the output. With the sender disconnected there is no current flow, the strip doesn't heat up, the contacts do not open up and you will read system voltage, be it battery or alternator. YOu sure you have a pressure sender not a switch? The sender is like a metal can, the switch is plastic.
Do you have a temp gauge? Does it work? If so the IVR is ok.
