Troubleshooting an oil pressure sending unit

[MDMoparDude]

Hey guys, all the gauges in my dash work except for the oil pressure gauge.  How should I go about troubleshooting whether it is the sending unit or the the gauge?  It might not have the correct sending unit, so if you would have pictures, that would help.  Car is a 70 Chally 440 six pack

[422STROKER]

  The sender is larger for oil guage vs a light.  Like double the size.

Tom

[Chryco Psycho]

grond the sender wire & see if the guage moves to the top , if yes you have a sender problem if not you have either a guage problem or a wire problem , check for pulsing voltage at the wire or guage if grounding the wire doesn`t move the guage

[Scatterbrain]

My car had a sender for a light installed and connected even though I had a gauge.  The guy before me didn't know what he was doing (if you've seen some of my posts about the floor pans then you know what I'm talking about).  I switched it out for the proper sender for a gauge and it started working.  The sender for the light is tiny, and somewhat skinny.  The sender for a gauge is huge by comparison, with a chamber for reading the pressure.

[Chryco Psycho]

yes the sender is a larger Bell shaped part

[MDMoparDude]

OK, I will try that Chryco.  I believe the sending unit is correct, based on your descriptions..

[FY1Cuda]

Our oil sender wasn't sending, and when I pulled it off I found there was a small piece of teflon tape blocking the sender's orifice.  Cleaned it out and it works fine.