Oil Pressure gauge (1 Viewer)

[Kilmacow]

I have a 75 series ute with a 1HZ and the oil pressure guage cycles between the bottom and top of it's deflection I have changed the oil pressure sender the condensor and the actual guage to no avail. Also the dash lights flicker every now and again can some enlightened help me sort this out engine runs fine oil pressure is good

 

[WarDamnEagle]

Sounds electrical and not mechanical related. Also sounds tough to troubleshoot. Are all the other gauges behaving normally?

 

[Kilmacow]

Sounds electrical and not mechanical related. Also sounds tough to troubleshoot. Are all the other gauges behaving normally?

The fuel guage doesn't work but temp and voltmeter work fine. I think it must be an earth issue somewhere