Oil Pressure Sensor Fix

Worked on the oil pressure sensor trouble shooting today, and think I have found and fixed it. I found a bundle of wires entering the G3X EIS that when tugged caused the oil pressure gauge to fluctuate. Strangely with Mom and Rachel helping, we discovered that it also caused the fuel pressure and manifold pressures to wiggle also. Here is the text from my writeup on VAF:

VAF Post

I may be closing in on it

Ok. Far too many hours in the hangar tonight but finally may have found the culprit: enlisted help from my family to watch the gauges while I hunted for wiring problems. Finally found that tugging/bending the large bundle of wires going into the 78 pin connector on the eis caused the oil pressure gauge to do is jumpy thing

Surprisingly it also disturbed the gauges for the manifold pressure and the fuel pressure. Checked my wiring diagram and found the following wires in common among those three gauges:
Three grounds spliced together and three 5v lines spliced together and also sharing the 5v pin with the two capacitive fuel level senders.

The 5v and ground splices used those heat shrink solder bands and both looked only partially melted solder. I heated both and got much better solder flow. Put it all back together and gauges now steady when flexing and tugging same connector wire bundle. Will fly tomorrow and test. But I’m hopeful it is found.

Thanks Walt for the offer but I will wait and test for a bit more. I had tried swapping gauges without recal just to see but didn’t carry it to far or fly that way.


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