Hello. I have an issue with my HZ75's oil pressure gauge. It's a 2H Diesel. The gauge is barely showing a reading. Idle 2000 revs I've put a gauge on to check the oil pressure which is fine. Idle 2000 revs I've tried 2 new senders and a quick earthing of the wire to the sender, the earth wire that attaches to the sender and the block sends the gauge needle to the high pressure level. Has anyone encountered this problem before? If so is there a quick fix or do I need a new gauge in the dash? Any help would be appreciated.