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Fuel level gauge now reads correctly

Bob Sawyer

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During the restoration of the '68 Charger, installed a new fuel tank and Spectra fuel level gauge. With 12-15 gallons of gasoline in the tank it would register only 1/4 tank at the most.
I drained the tank and removed the sending unit. I disassembled it and removed the resistor board. I did the same to thek8. rusted original sending unit. Surprisingly, the old resistor board looked good. I cleaned it up and installed it in the new unit. Checked the ohms and they fell right in the range of 12 - 75. Once everything was back together I tested it outside the tank hooked to the sending unit wire and grounded properly.
Finally, the gauge works as it should. I retested several times just to be sure.
I have the old fuel tank, so I cut a hole in it and installed the new gauge just to be sure the float did not make contact with the top or bottom of the tank when the float arm is fully up or down. If the new tank is anywhere close to the same dimensions as the old tank, I should be good to go.
I've attached a few pics for reference.

20200506_100855.jpg 20200506_100912.jpg 20200506_131547.jpg 20200506_143403.jpg
 
Hell, now me, you and 2 other people have a correct reading!
 
I had to do the same thing. So that's five of us. :thumbsup:
 
THanks for this ... I have my original sender for my 66 and it looks usable. I also have a new sender coming as well. This is very cool.
 
Hey guys, I just realized on that 3rd pic, I had installed the resistor board incorrectly. I did remove it and install it correctly.
Sorry about the confusion.
 
Hi Bob Sawer, I recently purchased a '71 road runner and the fuel gauge stays pegged on "E". I sent my entire instrument cluster out to Gary the tachman (to fix broken tac) and he confirmed mu fuel gauge is fine. How do I test the sending unit with a DVM? I'm competent with basis DC electronics. Thanks!
 
Hi Bob Sawer, I recently purchased a '71 road runner and the fuel gauge stays pegged on "E". I sent my entire instrument cluster out to Gary the tachman (to fix broken tac) and he confirmed mu fuel gauge is fine. How do I test the sending unit with a DVM? I'm competent with basis DC electronics. Thanks!
Around 10 ohms is full on the sender.
 
Why the hell can't these aftermarket sending units have the same resister units built like the original ones? All of them have the same problem.....MO
 
1/3 tank max on mine. I spent countless hours working on it to no avail.
I actually ran out of gas the other day after taking a few drives after coming out of storage, forgetting how much fuel was in it before I put it away. Lucky for me I was just about to pass a gas station going down a hill and I was able to coast in right between two pumps!!!!
 
Good thing I can look straight into the tank from the filter neck ! A visual is always reassuring
 
Sometimes the float actuator arm needs bending.

I had one sender unit that had an adjustment screw - so it was possible to adjust the length of the arm, making it easier to get full sweep of the float. The only drawback, was that the travel gave a much faster movement downwards on the gauge between 3/4 and E.

Bench testing of the sender unit is advised every time there is an opportunity.
 
When I was putting my car back together, I decided to have instrument cluster checked and tuned up. I too bought a brand new repop fuel sender thinking hey its new its gonna work. Im glad I brought it with me to the repair shop. The tech immediately rolled his eyes and said the repop senders are junk. He told me they are not even close to being calibrated to our cars. If I remember correctly, he said the repops are set up to match an aftermarket stand alone dash gauge. Luckily my tank sender was working fine, he cleaned it up and bent a new 3/8 metal pick up tube for me. Knock on wood, everything works just fine.
Something to consider when redoing things make sure gauge and sender are calibrated the same
 
Time to hunt down an old sender! I'm fed up with my repro. Thanks for the pics.
 
Has anyone tried a NOS sender with any luck? I've seen them listed but they are generally priced over $300!
 
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