Thread: Fuel Gauge Help
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Old 04-13-2021, 07:30 PM   #2
1970cstblazer
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Join Date: Jul 2003
Location: Elkland, PA
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Lightbulb Re: Fuel Gauge Help

Quote:
Originally Posted by mi396ss View Post
I installed a blazer tank under the box of my 1969 k20 with a new sending unit. I ran a new wire from the fuse panel to sending unit and grounded the sending unit to the frame. The tank is completely empty and the gauge shows 1/4 tank. When I remove the sending unit wire from the fuse panel, the gauge goes to 3:00. When I put a good ground on the fuse panel tab it goes to empty. When I connect the sending wire back up it goes to 1/4 tank. Any body have and suggestions on what’s going on? Thanks
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GM tanks are 0-90 Ohm resistance. When you ground the wire for the tank unit, the gauge should read empty. At 90 ohms, the gauge will read full. Disconnected, that is infinite resistance, so the gauge should max out past full. I would test the tank unit to verify resistance values.
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