I need some fuel sending unit experts please

Mattax said

10 ohm resistor between the Oil pressure gage connector and ground should bring the gage to H or approximately 80 psi
22 ohms resistance should bring the pressure gage to show middle, and anything over 75 it should show zero.
So either high resistance or no connection would keep the pressure gage from working.

PS. Like the fuel gages, replacement oil pressure senders aren't matched to the '60s gages.

Click to expand...

Thanks for the response.

So that is the problem I’m having. The tests I’ve done on the fuel system show the fuel gauge, IVR, sending unit and ground are all good. Wherein does the problem lie? Is there a separate ground on the rally dash that could be missing?

I did not test the oil pressure unit other than temporary grounding to see if the gauge needle responded. (No movement)

The voltage test on the IVR at the fuel sender connector was done with a power pro ( alternated positive negative) and separately by digital multimeter. This produced a broad range of voltages at various intervals but nothing that looked like consistent intervals.

Is it possible for the IVR to be partially functional ( enough for temp gauge but not consistent enough for fuel and oil pressure-both of those aftermarket items)