Oil pressure trouble

My reliable go to diagnostics with electrical is it is always the ground....

I have had many conversations with other owners about weird readings etc. and tell them it will be a bad ground, only to hear back that they have already checked that and after about an average of two further weeks of testing everything, they usually come back and tell me 'You were right, it was the ground'! 

It will be the ground...

I have had numerous ground issues. I have tested many and it showed a ground. The problem is it's a poor ground. If I have an issue I take a new wire and just run it around to make a good contact somewhere and to whatever I'm testing. Then I know for sure I have a good solid ground for a quick elimination test and it has solved a few of those electrical gremlin issues. Then I just replace the old ground. The plane's I see this on more often are planes like a Flight Design that is all carbon fiber and not all metal like some others. Plus sometimes wires get their insulation worn through and it's touching something.

Many thanks to all for this interesting living room talk-show, but I have ONE corrupted data and FIVE corrects one on the same EFIS which has only one ground. So I considères this not involved in my actual trouble.