Additional Oil Pressure Switch

Kevin,

Yes, I've pretty much made up my mind to go with the additional warning available on the Dynon.  I also agree with your comment no. 4, all three sensors are powered by the same output.  As I mentioned in another reply I suspect the faulty MAP sensor affected the output voltage (IIRC it was +5V) and that caused the Dynon software to detect a problem on all three sensors and "X'd" them out.  BTW my neighbor now carries a spare MAP sensor because of that incident.  Thanks for your comments.  Although I've never seen an oil pressure sensor leak, I remember that Ford had a problem with the brake fluid switch leaking which lead to a fire in some of their Explorers.  I don't need that problem!

You could generate a separate +5V regulated supply to power the MAP sensor if that was a concern. That would then remove a potential cause of the oil pressure sensor not reporting correctly.

Absolutely, I've also thought about a 25uF capacitor on the power lead of the MAP sensor, but so far we've only had one MAP sensor fail.  At our airport we've got three aircraft with Dynon avionics and I'll keep an eye on them.

Too late to be useful, but I get the OP's point. My factory install has two oil pressure sensors, remote mounted on the non-vibrating firewall. One, now fully electronic since I had all kinds of problems with the VDO sensors, feeds the oil pressure gauge. The other is just an on/off switch triggered at a very low pressure, to record engine running time. (Being a motorglider, there are two Hobbs meter, one for airframe (= master on) and the other for engine time.) It would be easy to wire in a buzzer/light to that OP switch, at first glance, but of course without some logic, it would buzz every time the engine is off and master is on. Not a big problem for a normal airplane, but I often fly with the engine off! Here's the block with the sensors - the line to the left threads into the oil normally occupied by the stock OP sensor.