Hope one of you experts can help me with this one. I have been having some strange behaviour from the gas gauge in my 66. No surpirse there I know. When I got the car the gauge was dead the whole time. I replaced the sending unit which is sending fine (checked variation in resistance) but still no change. Changed the constant voltage regulator exactly as it was previously mounted on the back on the instrument panel - attached to the metallic back plate of the instrument panel via a small screw. This made no difference either despite there being 1/2 - 3/4 of a tank of gas in there. All other gauges seem to be fine.
Now here is the strange thing. Last night I was looking at it again and noticed that if the constant voltage regulator is NOT screwed into the back plate of the instrument panel, i.e insulated from it, then the gas gauge springs to life. Unfortunately the TEMP and OIL gauges then max out constantly. Also on the screw that attaches the regulator to the back plate there is a male tag and a black wire running from it that has been cut by the previous owner - looks like it has been connected somewhere - maybe an earth ????
Can anyone please tell me exactly how the regulator must be installed for correct performance and what this black wire is there for because it is driving me mad???
many thanks.
Jonathan