1993 Cobra Registry

See attached video. I have been have a issue with my oil pressure gauge dropping to zero at idle (after warm up), rev the engine and it goes back up. Replaced the sender unit with a new one, and she went bizerk. Can my gauge pod be going out or what? That's the only gauge I am having an issue with. Any ideas?
Initial issue:


After replacing sending unit:
https://drive.google.com/open?id=0BwA6_ ... EkyeVVRbDQ

I would try another sending unit, then to be on safe side hook a mechanical gauge up to make sure you have oil pressure. I'm currently building a new motor for my 92gt because at cold idle it has 40lbs of oil pressure at cold idle and at operating temp it has 5, this is on a mechanical gauge.

Ha, that's a good one, can't say I've ever seen that one before. Looks to be some sort of electrical issue, a short of some sort.