Hi. I have a ‘74 1.8 that is carbuerated. The PO did not have the oil pressure sensor (idiot light) connected. There is only a spade connector coming from the sensor. A lot of wires have been cut back. I read that the sensore wire is red/green. I presume that would be true at both ends (instrument panel and engine bay). Does anyone know where I should be digging to find it? Thanks!

It is in the ignition harness. Goes to the relay board.

Found it! Thanks. Now I need figure out where it comes out of the relay board. That is the missing wire. Headed in search of a schematic of a 74 relay board.

It goes to Pin #1 on the 12 pin connector All 914s are identical regarding this. See attached harness diagram specific to your 1974 1.8L harness. The pin #s are cast into the 12 pin connector housing.