Is my gas gauge broken?

Dear Car Talk

Dear Car Talk | Nov 01, 1990

Dear Tom and Ray
I have a 1983 Camaro. The gas gauge indicator goes all the way to empty when the car is turned off. Then it goes all the way to full when the car is started. It never shows anything in between, no matter how much gas is in the tank. What's the problem?

RAY Well, John, we have good news, and we have bad news. The good news is that your gas gauge is working perfectly when the car is turned off. With the key in the off position, it's supposed to read zero.

TOM I guess you know the bad news. When the ignition is on, the gas gauge is supposed to tell you how much fuel is in the tank.

RAY The fact that the needle stays at "full," means that the gauge on the dashboard is working properly. Your problem is somewhere between the gauge and the gas tank. It could be the wire that connects the two, or the gas tank sending unit (the device in the tank that measures the fuel level and tells the needle where to point).

TOM And there's more bad news, John. Considering the age of the car, my guess is that the problem is in the sending unit, rather than the wire. Replacing that is going to cost you 100-200 dollars.

RAY If that's too much to spend, John, just try to remember to fill up the tank frequently. Then keep your fingers crossed, and carry a copy of the "Click and Clack Guide to Cheap Inns and Motels" in the glove compartment for when you miscalculate.

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