1965 Plymouth Sport Fury Fuel Gauge not working

bloopar

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Hey guys, my fuel gauge has never worked properly, and I have decided to turn to this forum for help again as this is stumping me. First, some background information regarding the problem:

Originally, it would start to move whenever you turned the key left or right but it would stop before getting to the E mark, however if I unscrewed the gauge cluster and pulled it out a bit it would start to read "properly", though I was never able to confirm this. This sounded like a grounding issue to me, however while diagnosing it for a few days I accidently fried the gauge, so I have to rebuild it.

Pictured below is the extent of the damage caused by me frying it after I took it apart:

fuel gauge fried.jpg

It charred the wire pretty bad, thankfully I had a quick reaction to it and was able to prevent an electrical fire or further damage to the gauge. Here is a picture of the rebuild I did, (I also had to replace the white wire with a copper wire because when I turned the key it blew up instantly):

fuel gauge rebuild1.jpg
I attempted fixing this the best I could, though a critical error I made was I used the wrong gauge of copper wire, (I used 24 gauge), which seems to not play nice at all and caused my temperature gauge to instantly move on start-up to about the middle before I shut off the car. Obviously, it is letting too much voltage through, which is why I need your guy's help on which gauge of wire I need and any other useful tips. I am also aware of the shoddy connections and soldering, I am pretty new to all of this, but I did test it with a multimeter and it was all connected fine. I appreciate any helpful responses and I hope this forum can help me solve this problem.
 

57fury440

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Are you sure the gauge is the problem? What about the sending unit in the tank? My '57 did the same thing when you turned the key to acc. or ign. On mine it was the float was shot. I replaced it with a new one and it works.
 

1970FuryConv

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When presented with an inoperative gas gauge, the 1st thing I do is ground the sending unit wire and watch the gauge.

If the needle goes to full, the gauge is OK.

If the needle does not move or moves only a small amount, either there is no power to the gauge or the gauge or sending unit wire has a problem.

Did you do this test before condemning the gauge?
 

Big_John

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Buy another gauge.

The coil on the right is the voltage limiter. Unlike later years, the voltage limiter is internal to the fuel gauge in 1965,

With BOTH of these wound coils, they wrap around a bi-metallic strip that bends with the heat generated by the coil. Change the size of the wire and you change the resistance and therefore the heat. The voltage limiter limits the voltage to 5 volts and does it by the contact opening and closing rapidly. The gauge works by a mechanical connection to the bi-metal strip.

Larger diameter wire is lower resistance, and will heat up more. You need to get the correct number of winds too as that changes the length which changes the resistance.

So... Maybe you can replace the voltage limiter with some sort of external electronic version, but the rest of the gauge is toast.
 

Mudeblue

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Assuming it is the gauge and not the sending unit/wiring and as Big John stated, the gas gauge has the voltage limiter in it which also controls the ampere gauge and heat gauge. I fought gauge problems for years before someone wised me up and it solved my multiple year problem. You can try to rewire or bypass but the quickest and easiest, and in my opinion, is to replace it/them. Many of the Chrysler models before and after 65 have gauges that look exactly the same and I would guess have the voltage limiter in them. Over the last week, I have been to 2 salvage yards here in Arizona and if I saw one, I saw a dozen which when cleaned and the dials painted would look good. If you can, get the complete set of three. As a consequence, I have a couple of sets in reserve; just in case. In the end, big problem but easy solution! Be sure to unhook the battery before working with the gauges. Voice of experience.
 

Sixpactogo

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I have a set of gauges for a 65 Plymouth. I removed them years ago from a parts car I had. They are untested but I assume they work. A while back I saw where someone replaced the voltage limiter in the fuel gauge with an electronic one mounted to the back of the printed circuit. That don't help you out with your fuel gauge but I can ship you this set for $50.00. The needles are faded and need new paint but I would think you could make a good set between this one and yours. Has the printed circuit and capacitor.

100_0632.JPG


100_0633.JPG
 
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1970FuryConv

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I have a set of gauges for a 65 Plymouth. I removed them years ago from a parts car I had. They are untested but I assume they work. A while back I saw where someone replaced the voltage limiter in the fuel gauge with an electronic one mounted to the back of the printed circuit. That don't help you out with your fuel gauge but I can ship you this set for $50.00. The needles are faded and need new paint but I would think you could make a good set between this one and yours. Has the printed circuit and capacitor.

View attachment 563882

View attachment 563883
Awesome help!!! Great member support!
 

bloopar

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I have a set of gauges for a 65 Plymouth. I removed them years ago from a parts car I had. They are untested but I assume they work. A while back I saw where someone replaced the voltage limiter in the fuel gauge with an electronic one mounted to the back of the printed circuit. That don't help you out with your fuel gauge but I can ship you this set for $50.00. The needles are faded and need new paint but I would think you could make a good set between this one and yours. Has the printed circuit and capacitor.

View attachment 563882

View attachment 563883
That's incredible. I would definitely be willing to buy that off from you unless someone else got to it first.
 
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