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Home >> GMC >> 1986 >> Jimmy 6.2 C >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Selector Valve - Electric >> Testing >> Selector Valve Harness Test
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Selector Valve Harness Test

  1. Fill one tank with 10 gallons of fuel, and other tank with 5 gallons. Remove harness connector from fuel selector valve and connect a good selector valve. Turn ignition on and depress selector valve switch. Note gauge reading for right and left tanks.
  2. If reading is different between tanks, replace selector valve. If no difference is shown, repair open circuit(s) in harness between selector valve and firewall connector. If fuel gauge operates, but not accurately, check fuel gauge.