I just had to go out and look! Dark out. Anyway there it was by the shut off valve. A tiny little round glass or plastic gauge a little bigger than a quarter with tiny blurry writing inside and a red marker needle. Has one red wire attached to it at the bottom. perhaps it is grounded to the frame via the tank?
Of course right at the distance where my bifocals don't work so I used a magnifying glass with a flashlight and I think I saw a blurry 1/4 up to the left at about 10 o clock and a 3/4 down around 3 o clock and an F just past that at 4 o clock? The red needle is just above the 3/4 mark at 2 o clock ----all blurring in and out of focus :(
There is a bunch of even tinier writing around the dial--can't read it.
So that means this gauge says the tank is almost 3/4 full, while the idiot light level says it is Full?
Can I trust that tank gauge?