Pressure switch + Hobbs meter ?

[455 Bravo Uniform]

My panel is open for an engine monitor installation. I’m going to be removing the existing straight bulkhead connector for oil pressure off of the firewall and replacing it with tee bulkhead connector.

I found this oil pressure switch. I don’t think it goes to anything. I don’t have an oil pressure warning light.

I had a Hobbs meter in the plane, but that was triggered by the master, not oil pressure. Perhaps the oil pressure switch has gone bad in the closed position. I’ll do some multimeter testing tomorrow.

Anything else you think it might have gone to?

Man, I hate looking behind the panel. I wanna rip everything out and start fresh,

 

[Ryan Klems]

That looks like the standard Cessna setup for the Hobbs meter. Someone prior to you probably switched the Hobbs to the master (was it previously used by a flight school?)

Is your engine monitor a primary engine monitor? If so, I'd mount the transducer forward of the firewall and just eliminate the oil coming in to the cabin (and any other fluid lines). If not, then you can probably just remove that switch and then attach your transducer to that port, most of them have a 1/8" NPT male fitting on the end that will thread right in after the switch is removed.

 

[Ed Haywood]

Most likely switched your Hobbs at one time. IMO that is a better method than switching by the master. My newly overhauled engine has a new Hobbs set to zero hours and switched by oil pressure.

 

[Gary Ward]

I looked in my service manual as I have one for a 182 and could not find it, but years ago mine was found leaking during a annual inspection. I replaced it and thought I read that they have 10 year life span until they should be replaced?
So if you keep it replace it with a fresh one.

 

[455 Bravo Uniform]

Thanks all. No, not a flight school plane.

Maybe the switch went bad and they just decided to hook it up to the master.

My new monitor is not primary.

My Hobbs broke about 2 flight hours ago. I decided to remove and not replace it.