fuel gauge sending unit, need output data, have strange readings Options

[SirAndy]

does someone have the exact numbers handy of what the fuel sending unit SHOULD put out? min/max voltage etc. (IMG:style_emoticons/default/confused24.gif)

i have about 4 gallons in the tank and the fuel light still comes on,
BUT i get only about 5.5 volt on it, so it's dim !?! isn't that supposed
to be more like a on/off switch thing and not a dim in/out light?
also, if i remove the bulb and measure directly, i get 12V !!!
and it's not the bulb. exchanged (known good) bulbs and get the same.
looks like it's going down to 5.5 V when under load! WTF!!!! (IMG:style_emoticons/default/blink.gif)

also, my fuel gauge doesn't do anything. first round of measuring showed 0.5 V,
then 10 minutes later it shows -0.1 V ????? (IMG:style_emoticons/default/wacko.gif)

soooo, anyone who has a manual handy?
thanks,
Andy