Temp gauge not working

Year i know, this is off topic, but I will ask anyway.
I have an old tractor, a Chamberlain with a 4 cyl Perkins desiel. It was missing all it's instruments so i bought a cheap set of gauges from the local Autobarn. Water temp, oil pressure & ammeter.
Oil pressure works, ammeter might if i ever conect the alternator.
Water sender would not screw into the block, I had do use 2 adapters & a through conect to adapt the sender unit into the block. temp gauge did not move, I treid bleeding the sender thinking I had an air lock, no joy.
I then bought a genuine temp gauge from a tractor sales. I tried this gauge by putting the sender in hot water, it worked fine. This sender screwed straight into the block without any of the adapters. BUT this gauge does not move either.
Anyone got any suggestions?
I have only run the tractor for a max of 20 min at a time and don't work it hard but the gauge did not move off the cold position.
I have though that the thermostat might be missing, so water is always circulating and not getting hot, I have not checked this yet, any other suggestions?

from Marty.