72 Dart
I have got to get gas gauge working and losing patience. I grounded sender wire and no movement in gauge at all. Took out small voltage regulator (on panel) and can't determine if it's bad. Put 12v on center terminal and get 12 volts on both other terminals???? All other gauges and lights are working. If anyone has additional troubleshooting steps, I'd really appreciate. Thansk....Gary

If your temp guage is working properly then the voltage limiter in the dash is not your problem. You either have a bad sending unit or a 'open' (broken) wire going to it. If possible try known good sender. Hook it up the the feed wire, turn of the ignition and work the float (slowly). Have a helper watch the guage for movement. If it moves then you sender is FUBAR' if it dosen't then you have a 'open' (broken) sending wire which will involve some time and disassembly to locate.

Confession.....I've never removed a gas gauge sender. I presume the tank must be removed and the sender comes straight out??? I will try to ohm out the sender wire between the inst panel and tank to see if open. Thanks much....Gary

Wait a second.

Which end of the sender wire did you ground?




Your problem is either the sender wire or the gauge. The sender's condition is unknown as grounding the wire removes the sender from the circuit. You now have to ground the sender terminal of the gauge to see if there's movement. Should it full sweep, you will have to find the break in your sender wire. If it doesnt, the gauge is defective.

But since you probably already have the tank pulled from the car, you can use a multimeter to check resistance of the sender itself. Use a BRASS drift to knock the retaining ring counterclockwise, and remove it. Place one lead of your meter on the sending terminal, the other lead to a good ground on the outer surface of the sender. Sweep the float up and down and verify the resistance is changing smoothly. You can also visually check the resistor and moving contact for wear. Check the strainer sock for tears as well. That should cover all your bases.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

...then your instrument voltage regulator is ok. Suspects now would be your sending unit within the tank or broken/interrupted wiring from the tank to the gauge.
You can check your sending unit without removing it from the tank with an ohm meter: Crawl under the tank, disconnect the wire to the gauge (at the tank) and insert one probe to the wire going into the tank and the other to a good clean ground. You should get a reading around 8-10 ohm if tank is full and 60-75 ohm if tank is empty.

If this proves ok, with assistance from a helper to visually check if your gauge moves or not, turn the key to the run position and ground the terminal going to the gauge. It should peg to the full end if wiring is ok. Don't let it stay pegged more than a few seconds, the resistance in the gauge will burn...

Good luck

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Rafa

Hecho en México

Is it cold where you live? I only ask because during cold snaps my car's gas gauge likes to hibernate, every morning I drive it feels like the lotery, "Is it working?" Right now it's working great, and it doens't die during the summer, I personally think it's a little gnome that in the cold wraps its self up in my gas gauge wires.....

Then again, it's one of those things that I really haven't researched because whenever it decides not to work I start filling up every four days to avoid problems and don't look forward to looking for what the real cause is.

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My car may be slow to sixty, but at least it's been reliably slow to sixty for more than thirty years.

Ive noticed that too! When it gets around five degrees F the gas needle stays on empty until the cab warms up. Ive always thought it's because the bimetallic strip can't get hot enough to move the gauge when the cab is so cold. It never fails to work entirely though...

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

With your help, I finally found the connector behind the kick panel which was corroded and open. At least now I know a lot more about gauge troubleshooting. Thanks much to all!!!