Thanks, from a likelihood perspective, would you say it's more likely the sender? I'm not completely sure what the resistance should be at 0 psi but it's 243 ohms.
While I understand how an electrical circuit works, it's unknown to me how that signal of 12-14v gets manipulated by the ECU and passed to a gauge. Please let me know.
I'm not getting the audible alarm anymore. I think it ended up being the drive lube. However, if I take the wire off the sender, I'm getting 0psi on the gauge. If I put it back on the sender, I get 80+ psi. Do I need to ground out the wire to the sender to completely test?
But I narrowed down the signal changing to the output of the wiring from the sender right? If the gauge was bad, it wouldn't have changed output based on changing signal from the sender. Or maybe I'm wrong. I did find out that actual oil pressure is normal.
Another Update: I was able to take the sender out and I installed my mechanical gauge (what a pita). Started up and 40-50psi at idle which is perfect. Is that a nail in the coffin for the sender?
Update: I pulled the single wire off the sender and key on engine on I'm at zero. Plugged it back in and I'm still at 80+ so I think that rules out the gauge right?
So I just did the oil change and unfortunately the oil pressure gauge is still pegging at 80psi plus. I wiggled the leads on the gauge and I wiggled the leads on the sensor. I did fill yup the drive lube and the beeping did not go off. I can barely reach the oil pressure sensor but what would...
Wow, thanks for all the replies! I was strapped for time last year and didn't get to changing the oil. I was actually starting it yesterday to try and get the oil warm so I could change the oil. I did have low gear lube so I'm betting the alarm is on for that instead. Hopefully an oil change...
I'm not exactly sure how the alarm works. Does it use the same output as the gauge and therefore the sensor could be the issue? Or, if the gauge is used and that causes the alarm?
I just started my 2004 EFI 5.7 Mercruiser engine for the first time this year and I immediately got a warning buzzer and the oil pressure gauge was pegged at 80 psi. It's always been in the 40 psi range. I did not hear any mechanical tapping noises like starvation of oil from a blockage. Nothing...