fuel gauge not reading gas at all

[Michael Maresca]

good afternoon All, I restored my entire dashboard on a 1967 Plymouth GTX. Everything works fine except for my fuel gauge. I put 5 gallons of gas in the tank so it should read a 1/4 tank. I believe my tank holds 19 gallons if I am not mistaking. Anyway, I am not good with anything electrical or reading OHM meters.

I live in Ocean County, NJ. Does anyone know of a good mechanic that can fix my problem that is close to my area? zi have a new tank in the car with an after market sending unit. I believe the grounding strap is still in place. I want to get this fixed before I install the Windsheild. this way if I need to lower the dashboard or pull out the Instrument cluster, I will be able to. Any help here please.

 

[Kern Dog]

Hey there,
There are times like these where a guy puts his car together and somehow didn't hear of all the problems that others have been dealing with for years.
This is one of those times. I dealt with it in 2002, others here have seen it before that!
It is an unfortunate fact that aftermarket fuel sending units are ****. They are not accurate, they only seem to serve as an advisory that there might be gas in the tank.
The original sending units were not perfect but they were far more accurate than what is being sold now.
Why?
The originals measured the fuel level on a NON linear curve. New ones are made using the cheaper linear model so they often read empty when you actually do have fuel in the tank. Sometimes they read 3/4 even though the tank is full. They really do suck.
You can test the gauge by having someone sit in the car looking at the gauges (Ignition ON) while you remove the wire from the sending unit and connect it to a negative ground. If the gauge is working, the needle will sweep over to FULL right away. Do not do this for more than it takes to move the needle.
If the needle moves, the sending unit works but is simply not accurate. The best advice I can offer is to try to find a good original and see about having it restored.
If the needle stays still, the problem could be in the dash itself. There is a voltage limiter pressed into the back side of the instrument panel...

I'm no electrical expert either but these do go bad, cutting power to the fuel gauge.

 

[BigFlo]

What did you do and replace when you restored your dash? Was it all original before it was restored? Did the fuel gauge work before it was restored?

 

[dadsbee]

 

[Michael Maresca]

What did you do and replace when you restored your dash? Was it all original before it was restored? Did the fuel gauge work before it was restored?

I correctly painted the outside of the dash again, reckoned the moldings. had the glovebox door and Instrument cluster bezel redone. cleaned up all knobs and connections. and the fuel gauge never read correctly. If the tank was full it would read half full.

 

[Michael Maresca]

What did you do and replace when you restored your dash? Was it all original before it was restored? Did the fuel gauge work before it was restored?

sorry, I didn't answer one of your questions. But yes, the entire dash and Instrument Cluster was original.

 

[Jerry Hall]

The voltage limiter controls both the temperature and fuel gauge in 1967. If the temperature gauge is working and the fuel gauge is not, it's not the voltage limiter. As stated above test the fuel gauge.

 

[BigFlo]

If the gauge doesn’t work with the above test, I would loosen and re-tighten the nuts on the back of the dash circuit board. Just couple of turns each way - no need to remove. I took Keen Dog’s picture and circled the nuts where the fuel and temp gauge connect. There could be some corrosion preventing the electrical connection.

 

[retractable]

I just had the same issue with a 66 satelitte. New tank and new sending unit. Put in 5 gal of gas and no reading. I had check the se ding unit out before I installed it. I filled up the tank with gas and it worked. I don't know how accurate it is yet. I only driven it 15 miles so far..

 

[68BabyBlue]

I had both my temperature and fuel readings go bad, but I got lucky that they failed at different times, so I was able to rule out the voltage limiter. I went through three temperature sending units which wouldn't read correctly, two of them later Mopar NOS, finally bought some old used OEM from a member here, and the first one I installed has been working fine for a year. The reproduction fuel sender quit about that time. I'm keeping track of miles between fill ups, and will use that process until I can get an original unit.

My car was restored over 20 years ago, and has a lot of its original parts, or NOS. Frustrating how the parts quality has declined since then.