I am reading 55 ohms at the oil pressure sender under idle which translates to 45psi so I know the pressure is good. The pressure gauge on the cluster simply doesnt work. i have a yellow/red wire hanging, When I connect it to the pressure sender ohms drop to 0. Can someone confirm the color wire that is supposed to be hooked to the sender because I dont think I have the right one but there are a couple more under there.

 

The plug that connects to the sender is unlike any plug (shape of plug) in the engine bay. Are you stating that this particular plug might have been placed (fastened) on the wrong wire? I believe the wire color is Y/R.