short to the gas guage

[pink panther]

Ok, I must have a short to my gas guage, the gauage sometimes works fine other times not at all. The other guages in the cluster do operate properly so would that mean it is at the tank?

[MEK-Dangerfield]

I think you have the opposite of a short. If you had a short, it would read full all the time. You can check that the pick-up tube on the sending unit is grounded securely by a strap to the solid fuel line. Is the wire to the sending unit on nice and snug?  Also, as you suspect, it could be your sending unit.


  Mike

[Mopar73340]

I think you have the opposite of a short. If you had a short, it would read full all the time. You can check that the pick-up tube on the sending unit is grounded securely by a strap to the solid fuel line. Is the wire to the sending unit on nice and snug?  Also, as you suspect, it could be your sending unit.


  Mike

   Sounds like a bad ground. You can check your wiring by grounding the wire where it hooks to the sender and **momentarily** turning on the ignition switch. The guage should read full scale. If it does the problem is most likely the sender or a bad ground.

[pink panther]

Thanks guys, I will check the ground hopefully that is the problem.

[pink panther]

I looked at this and am stil confused. I have the tube coming out and then soft hose going to the electric fuel pump, then soft hose to the hard fuel line. I only see one wire coming out of the sending unit, wouldn't that go to the guage?  Where do I try and place a wire to see if it is the ground as mopar 73340 suggested?

[Bullitt-]

The wire that goes up thru the trunk from the sending unit is the feed to the gauge.  A ground strap was originally clipped on between the outlet tube of the sending unit & the metal fuel line.  If the strap is missing a wire can be fastened to the sending unit & attached to the frame to provide a solid ground.

[Mopar73340]

   Try grounding the wire froum the guage (the one comming through the trunk floor) directly to ground momentarily (a couple seconds) and see if your guage reads full scale. Then run a piece of wire between the fuel line that is going to the front and the tube comming out of the sender or any good ground to be sure the sender is grounded. If that is missing it is most likely your problem.

[pink panther]

Ok, how was it working before if I didn't see the ground? Anyway I hooked a wire to the sending unit and grounded it to the chasis, the guage came up, but not full as I'm probably pretty low on fuel. Does that mean it is the ground and not the sending unit?  How hard is it to replace the sending unit? do you have to drop the tank?

[ted]

IT  should read full, sounds like a bad guage.

[Bullitt-]

PP, Sounds like you have solved the problem....It is possible that a circuit was being created from the tank to the body via the tank straps. Check what it is reading now, add about 4 gallons & it should come up 1/4 more of the gauge.  These gauges were never all that accurate as the mechanical float & resistor does not move from full till you have burned a couple of gallons off so i would not condemn the sending unit just yet. From what I understand they can be removed but the LH exhaust heat shield must be removed 1st.

[Mopar73340]

   The sending unit is easy to get out once the exhaust is out of the way. There is a lock ring which holds it in place, but like said above, make sure that is the problem before you change it.

[pink panther]

Another question, since the ground is strapped to the solid fuel line, can it be grounded anywhere along the solid fuel line? Or if I was looking for a ground it would only be at the sending unit?

[Mopar73340]

Not sure I follow your question, The short 90* turn on the outlet of the fuel sender or pickup had a jumper strap across where the rubber fuel line is 5-6" long approx over to the main fuel line running to the front of the car. The sender gets it's ground from the main fuel line which is clamped to the frame through this strap. It is possible that the sender is grounded through the tank by the straps that hold the tank in place but this is a bad ground usually. You can hook a ground wire from any good ground to the sender.

[cowboy]

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Now I'm lost to..

Somebody please load a pic. of sending unit, and ground solution.....

[Bullitt-]

Here is a good improvised ground