I have an 86 BRAT GL EA81 car and I have rebuilt the the oil pump and purchased a new oil press sending unit. Prior to the rebuild my oil pressure gauge would stay pegged out. After the change, The needle barely moves up at all and doesn't even reach the numbers so i suspect the new sending unit to be faulty.
After installing the pump i noticed i have a pressure switch for a dummy light as well as a sending unit for pressure reading but i only have one wire. Where is the wire i am supposed to connect to the pressure switch?