Re: Why Would An Oil Pressure Sending Unit Fail In Less Than A Year?
Subject: Re: Why Would An Oil Pressure Sending Unit Fail In Less Than A Year? by BillH on 2011/2/22 21:41:00
Quote:
rayquayle wrote: Quote:
bogus wrote: I am digging deep here, Ray, so bear with me.
IIRC, the oil pressure switch is normally open. So when it fails, it fails open, and that is why it reads 80 psi when failure occurs.
If the wiring dies, meaning a shorted circuit, then you get a 0 reading. When the wiring just breaks and there is no short, then you get 80.
Does that sound about right? I have never heard of the OPS failing and doing anything other than reading 80 psi.
You've got it right Andy, but they can and do fail open, shorted and anything in between. I have one in my toolbox that is stuck at about 50 Ohms that yields a pressure reading of around 45 psi at all times as a result. Don't ask why it is still rolling around my toolbox!
You guys are dead on. I do think it's important for J3 to inspect the harness to see if it's grounding anywhere.
