so working on this 69 charger and the oil gage is not working the gage bench test good wiring test OK swapped senders still no good should the sender have conductivity between the the plug on top and ground at 0 oil presser

No. Have you tried a mechanical gauge to make sure you have oil pressure?

yes

If you are using thread sealer or tape on the sender it won't work because it uses the block as a ground. If you ground the sender wire and turn the key on does the gauge rise? Testing it that way tells you the gauge is good but don't let it peg the gauge or you can burn it out.

no thread sealant used and gauge test good by grounding the wire

Obvious questions. Is the connector on the sender wire clean and free of rust and oxidation? Does it clip firmly to the sender? If the wire is jiggled while the car is running does the gauge move at all?

new wiring hares clip tight gauge twitches a little on sender but sweeps fine wean grounded

Was the mechanical gauge screwed into the same spot as the sender when you tried it?

yes 80 + psi

Im thinking the gauges 2 are both bad looked at the hemi charger in the shop and the needle does not swing as far left wean car is off if you put 9v to just the gauge it will twitch a couple times then swings right it dose the same thing wean in the car and you ground the sending wire so im thinking that they only work with full voltage

Full voltage at the gauge is only about 5v. The regulator on the back of the gauge cluster works like a turn signal flasher turning on and off to supply a 5v supply from a 12v source.