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Gas gauge misreading

Discussion in 'Chevy Trucks' started by raceman6135, Jul 3, 2001.

  1. raceman6135

    raceman6135 Member
    Messages: 61

    My 1986 C20 crew cab has dual fuel tanks. They have both been replaced within the last 2 years and the sending units are not much older than that.

    The other day I noticed that the level in my one tank was quite a bit lower than I thought it should be. I had parked in a different part of town over night and suspected that maybe some kids had siphoned some gas from my tank.

    I refueled that tank, but the level didn't show a full tank. In fact, it would not read above 3/8 of a tank (before I refueled, it read 1/4).

    I tried switching the tanks over to the other one, but it too would only read between 1/4 and 3/8.

    The valve and solenoid are working as I can hear it change position when I move the switch from the right tank to the left and back again.

    Some people have suggested that it may be a bad ground behind the dash causing the gauge to read incorrectly, but I have not been able to locate a bad ground.

    Does this mean I should head to the wrecking yard or the dealer and try another gauge? Or is there another area of the electrical system where I should do some more investigating before replacing the gauge?

    Thanks for any and all input.
  2. 75

    75 PlowSite.com Addict
    Messages: 1,382

    Does the gauge read correctly when the other tank is selected?

    Couple of ideas to check: The connections on the back of the dash switch for tank selection, and both the ground connection and sending unit connection at the tank itself.

    I think the dash cluster wiring consists of 1 big printed circuit and the gauge just "plugs" into the cluster, so I'm not sure about a ground problem there.