Ken Foley Bonnyville, AB Canada 01 Fleetwood Discovery 3126 CAT Oil pressure guage flicker and went to zero, I stopped and checked the oil it was okay, no strange sounds, everything appeared normal. So I went to frieghtliner in Nashville and bought a sending unit and replaced the old one. Tried it and still zero pressure, so I went and bought a new oil guage and installed it. It went to max and no veriation, so I considered the possibility I had crossed the fuel guage wires and oil guage wires. So I reversed them but the readings were still the same. Both plug ins are the same, and all four wires are coloured the same and both readings are the same, so I am at a loss. Any ideas of what may be wrong or what I should be doing or not doing. I did try putting a manual guage near the sending unit, it confirmed my oil pressure at 50 lbs.