Gas gauge . This is what I have tried.

[Canadian1968]

I can't seem to get my gas gauge to read correctly. I just pour 5 gals into the tank so I know this should give me approx a 1/4 tank reading.
The sending unit is new. I tested resistance and it changes as I swoop the bobber from top to bottom.
I check for continuity from wire end at sending unit to connector by ebrake. I grounded the gauge wire at the connector by the ebrake. the gauge swoops to full.  I even pulled the unit and bent arm down a bit thinking that maybe the float was not sitting low enough in the tank.
As soon as I turn the key on the gauge will move but the most I can can get is a reading right on empty . Key off  the needle sits about 2.8th below empty .

Temperature gauge works oil pressure tries to work but I think it sticks a bit .  Should I be looking at the voltage regulator on back of the gauges ?

[TommyGun]

Make sure the float doesn't leak. Take the sender back out and carefully un clip the float and shake it to see if there is gas inside.My car had the same problem.

[rebby]

Have you tried putting in anymore than 5 gallons? Current repop senders seem to read low. Here are the results of some testing that I did -> http://www.dodgecharger.com/forum/index.php/topic,123709.0.html

[Canadian1968]

when I had the sender out I made sure the float worked in a bucket of water

[Bronzedodge]

You did replace the ground strap when you put the new sender assembly in?

[Dino]

Sounds like you need to calibrate the gas gauge itself. Take it out of the dash (I know, pita) and hook it to the sender. With a small flat blade screwdriver you can adjust the reading from the back. There's a hole on each side. I did mine by removing the sender and I did all of it on the workbench by measuring the travel of the float and finding where 1/4, 1/2, and 3/4 were. Then I tested it in the tank and tweaked it a bit more. Reads spot on now.

[Highbanked Hauler]

Sounds like you need to calibrate the gas gauge itself. Take it out of the dash (I know, pita) and hook it to the sender. With a small flat blade screwdriver you can adjust the reading from the back. There's a hole on each side. I did mine by removing the sender and I did all of it on the workbench by measuring the travel of the float and finding where 1/4, 1/2, and 3/4 were. Then I tested it in the tank and tweaked it a bit more. Reads spot on now.

    Could you just fill the tank and set the gauge to full ?  Mine sent me on a 3.5 mile walk last Sat. because I ran out of gas and it still said 1/8 full.. It has a Layson's I  think it is sender and original gauge which never was right since I had the car.

[Dino]

Sounds like you need to calibrate the gas gauge itself. Take it out of the dash (I know, pita) and hook it to the sender. With a small flat blade screwdriver you can adjust the reading from the back. There's a hole on each side. I did mine by removing the sender and I did all of it on the workbench by measuring the travel of the float and finding where 1/4, 1/2, and 3/4 were. Then I tested it in the tank and tweaked it a bit more. Reads spot on now.

    Could you just fill the tank and set the gauge to full ?  Mine sent me on a 3.5 mile walk last Sat. because I ran out of gas and it still said 1/8 full.. It has a Layson's I  think it is sender and original gauge which never was right since I had the car.

You could but there is no guarantee it will read right on the rest of the scale. When my tank is full the gauge will be past the full mark, when it's near empty it will be below the empty mark. 1/4, 1/2, and 3/4 are pretty much on the money. If you have 20 gallons worth of gasoline storage then try to fill the tank with 5 gallons and set the gauge to 1/4. Add another 5 and see if it goes to 1/2 or just over. Add another 5 to get it to 3/4. At this point you may need to tweak the mechanism on the right of the gauge. The left side does the travel under 1/2, the right side everything above. The problem is that once you tweak one side you will likely need to tweak the other and it's a bit harder pulling gas back out and starting over, but you'll be able to get close.

Alternatively you can buy a few resistors and use a 12 volt power source to tune the gauge on resistance alone. In essence that's what I did when I used the sender on the bench, but it's more accurate because you're testing with the actual resistance the gauge will be seeing. I'd still do it that way. If you can get the car off the ground a bit and lower the ale, it's easy to remove the sender.

[green69rt]

You did replace the ground strap when you put the new sender assembly in?

Check this!  The sending unit will not have a ground and will not indicate if the grounding strap is not installed.

It looks like this and grounds the sender to the fuel line.

[Canadian1968]

yes I do have the sending  unit grounded .

regarding the calibration can I use volts instead ? 5 volts should give me full 2.5 approx half . ? I am thinking just using 1.5v batteries to get my readings

[Dino]

yes I do have the sending  unit grounded .

regarding the calibration can I use volts instead ? 5 volts should give me full 2.5 approx half . ? I am thinking just using 1.5v batteries to get my readings

You sure can. I had bought a new solid state limiter for the instrument panel at the time and used that hooked up to a car battery so I was sure the reading would be the same once installed. But I tried it with regular batteries afterwards and the readings were pretty much the same.    
It's good to have a few used batteries alongside new ones so you can combine them to have the voltage you need.

[Highbanked Hauler]

You did replace the ground strap when you put the new sender assembly in?

Check this!  The sending unit will not have a ground and will not indicate if the grounding strap is not installed.

It looks like this and grounds the sender to the fuel line.

     mine is badly rusted so I clamped a wire to the 3/8 tube of the pick up and ran it to a screw in the body and am going to ground the body to the negative post of the battery

[poppa]

http://www.dodgecharger.com/forum/index.php/topic,57971.0.html

may help???