The voltage stabilizer ( or regulator as you call it) is designed to supply a steady 10 volts to the temp and petrol gauges. (Actually the original stabilizers are electro mechanical and only simulate 10 volts) You should not use full 12v battery current to accurately test the gauges. There are many sender units being sold as being suitable for our cars, unfortunately few will give the readings we might expect.
The middle of the gauge should be a running temp of approx 75 degrees C and the H 100 degrees C. Senders are negative temperature coefficient, resistance of senders possibly too high. The gauges can be adjusted. Takes some faffing about , use thermometers, the slots behind the tiny cork plugs on the back of the gauges, when moved, will affect the needle. Be prepared to spend hours to get it perfect. Gauge needs to return to zero when off, moving the slots will affect rest and running positions of the needle. Doable but will chew up some time. After all, you did say you have some OCD in you.
Thank you very much, would you try making a video on ALL the gauges in the dashboard so we ALL can diagnose each Smiths gauge and accurately know what’s working and what’s not… thanks again.. Salute
