"T" into the existing oil pressure gauge with brass pipe fittings. This way you will have the original oil pressure gauge and the mechanical oil pressure gauge. Don't forget to use thread sealer.
Do you mean an oil pressure gauge? Not tach?
You will need to remove your oil pressure sending unit and install a mechanical gauge to get a true reading. You need to start out cold and write down the pressure reading and also once it warms up to operating temperature. If the pressure gauge is not the same as the mechanical one you have a bad pressure switch.
Screw out the oil sending unit. Put a "tee" back into the hole. Screw in the oil sending unit for the light AND the fitting for the mechanical oil gauge.
I feel sure you have checked to see that the engine has oil in it. You need to install an external oil pressure gauge, the mechanical type and check for pressure. If it shows that you have oil pressure then your sending unit is defective.
mechanical
The gauge should be electrical.
Connect the wiring harness to the back of your oil pressure gauge. Secure the oil pressure gauge with the retaining screws.
how to install the oil pressure gauge on a Chevy 350 small block
The oil pressure gauge in a 1999 Ford Explorer is ELECTRIC
Pressure Indicator is any instrument that indicates pressure. Pressure Gauge is also a type of pressure Indicator. It is a mechanical device. Pressure indicators can work on mechanical deflection (in case of pressure gauge) or Piezo electric effect, change in capacitance, change in inductance etc. These are generally digital type instruments.
Yes you can but, I would advise adding the mechanical gauge to the system but leaving the original intact.
install an oil pressure gauge