Hi, I was wondering if anybody could help me with the wiring of my Oil Pressure Gauge. The only diagrams I can find show a single wire sender to the dash cluster. Does this operate the Gauge and Low Oil Pressure Light? Or should my GT have a 2 wire sender? Cheers
Whether you have an oil light, or a gauge, it'll be one wire, the ground is the body of the sender screwed into the block. Now, an idiot light uses a switch sender, and a gauge uses a potentiometer sender. The following pic may be from the 1966 Ford shop manual, for the 390 and 428 CID engines, but the actual senders are exactly the same through the 1990s.
Thanks Handy_Andy_cv64, I have a a single wire from the sender to the dash cluster. Does this operate the Gauge and Low Oil Pressure Light?
If you have both a guage and an idiot light for oil pressure, that combo would require two separate wires and senders. As noted earlier, the light uses a simple pressure switch while the guage uses a potentiometer type sender. Both connected to one wire is a non-compatible combination. Both versions use the engine as a ground. Never seen both on any Ford from the factory, my Mercedes, yes, the Lotus Europa, yes, but not on any Fords.
It's possible someone who owned this Ranchero before you may have installed an aftermarket gauge, or may have attempted to install a factory sport cluster. I think I still have my 1974 wiring diagrams in storage; if I do, I'll post up the relevant diagram wiring colors for you to verify what is what.
