Gas gauge

[1974 dart]

I will fill up and after driving 10 miles it goes down to empty. I have already replaced the sending unit what else can I try? It is on a 1974 dart

 

[bbrroowwnn]

You have a 426 Hemi in there? If so that is normal .....LOL ...JK

 

[Rocky_JS]

check your clip on ground at the sender.

 

[Mr.FT]

Could be the Bi metal strip in the gauge itself. If so member here Redfish may be able to help. He calibrated mine and it is much better now.

 

[BillGrissom]

You need to break the link and test both ends. Use a multimeter to measure the resistance signal of the gage, use a resistor to feed a fake signal into the gage. You get at the wiring in the "body connector" behind the left foot "kick panel". Several posts with more details.

 

[Mopar to ya]

Try putting in more than 89 cents at a time? You need to check the resistance signal - X2 to BillGrissom.

 

[daliant]

Also check the nuts that hold the gauge into the cluster, they could be loose or just not making good contact.

 

[1974 dart]

I already checked resistance and it's how it should be and everything is tight on the back of the dash

 

[67Dart273]

Does the temp gauge seem to work OK?

Got to Radio Shack and buy 4 100 ohm 1 watt resistors, and wire all 4 in parallel. Put them from the sender wire to ground. If you don't feel like crawling underneath, you can access the connector at the left kick panel. This should give you almost exactly 1/2 full, to check the gauge accuracy, the wiring, and the voltage limiter.

You can also check the temp gauge the same way, with these resistors, just substitute the resistors for the temp sender. Should give you 1/2 scale.

If both are off about the same, I'd suspect the voltage limiter. If the fuel gauge (example) is off, but temp is close, suspect the nuts on the back of the gauge, or the gauge itself. After all these are HOW old, again, LOL?

 

[RedFish]

Check resistance across the gauge ? Get about 12.5 ?