I have a 1974 Chevy C10, (half ton stepside, 2 wheel drive). I have a replacement fuel gauge from . The gauge reads relatively correctly, (slightly above full when full). When I turn off the key, instead of remaining where it was it climbs as if the sensor line was open and there was voltage applied. I have another fuel gauge from a 73 model that works and does not do the described behavior. (I would use it but it does not have a window for the brake warning light). When i turn the key back on the gauge goes to the correct position. I cannot figure out what is driving the meter when the power is off. Anybody seen such bizarre behavior on your fuel gauge?? Thanks for any response.