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I've got a new tank and sending unit I put in my 64 I'm working on. I've also just installed a new Rebel Wire wiring harness. I can't get the fuel gauge to work. The gauge is probably the original one and I have no idea if it's good or not. I clipped the sending wire terminal off the old wiring harness and soldered it to the new sending wire. I clamped a wire to the sending unit nipple and grounded it to the body but it still doesn't work. I have a good wire with two alligator clips and I clipped one to the locking ring and clipped it to the same terminal I have the other wire attached to the body. Gauge still doesn't move. I have a new low voltage regulator and it's working because I checked it with a test meter. I'm thinking the next thing is to buy a new gauge since nothing else is working.
 

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I've got a new tank and sending unit I put in my 64 I'm working on. I've also just installed a new Rebel Wire wiring harness. I can't get the fuel gauge to work. The gauge is probably the original one and I have no idea if it's good or not. I clipped the sending wire terminal off the old wiring harness and soldered it to the new sending wire. I clamped a wire to the sending unit nipple and grounded it to the body but it still doesn't work. I have a good wire with two alligator clips and I clipped one to the locking ring and clipped it to the same terminal I have the other wire attached to the body. Gauge still doesn't move. I have a new low voltage regulator and it's working because I checked it with a test meter. I'm thinking the next thing is to buy a new gauge since nothing else is working.
Test your fuel gauge, it's easy.

The gauge has only 2 terminals. One gets power from the low voltage regulator the other goes to the sender.

With the key on, take the wire that goes to the sender an briefly ground it.

I usually find the sender wire at the gauge, and hook a jumper to it so I can momentarily touch it to ground somewhere at the dash with the key on (gauge powered).

If the gauge is good you will see the needle move.

HTH
 

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I've been out there checking some things since I posted. The tank has about 5 gallons in it and I got 59 ohms on the test meter. I checked the fuel gauge and have 13.8 to 14 ohms. The cvr is a new one I got from Melvin's or Macs, can't remember. When I checked it last week I was getting between 5 and 6 volts. Today it's only 1.3 to 1.4 and the red light is on the test meter. I swapped it out for the old one and the test meter light is blinking green and it can't get a good voltage reading. Now the fuel gauge needle will move, but only up to the E mark. I do have the gauge cluster grounded.
 

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I've been out there checking some things since I posted. The tank has about 5 gallons in it and I got 59 ohms on the test meter. I checked the fuel gauge and have 13.8 to 14 ohms. The cvr is a new one I got from Melvin's or Macs, can't remember. When I checked it last week I was getting between 5 and 6 volts. Today it's only 1.3 to 1.4 and the red light is on the test meter. I swapped it out for the old one and the test meter light is blinking green and it can't get a good voltage reading. Now the fuel gauge needle will move, but only up to the E mark. I do have the gauge cluster grounded.
I don't mean to sound condescending, but are you aware of how the cvr works?

Basically it is a thermal on/off switch that "pulses" the 12 volts to get an average lower voltage for the gauge.

Most hand held testers/voltmeters don't work well with pulsed voltages. They have trouble showing a reading.
They are generally meant to measure steady voltage.

If the gauge moves when you ground the sender wire it tells you that the gauge is capable of working, and that the cvr is passing voltage.
Calibration is another matter...

Here is a scan from my MOTOR Manual about dash gauges.

See if this helps.
 

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You're not. I didn't take it that way. I had read some place else that a test meter would act that way due to the pulsing. That's what it was doing. What gets me is the new one actually didn't pulse like that. It gave a steady voltage a few days ago, but now it's less than two. That's why I swapped it back out for the old one. I may get some more gas tomorrow and pour in the tank to see if it will move more. My 66 Chevy II I restored a few years ago didn't have a cvr for the factory gauges. Guess Chevy didn't see a need for them or designed their gauges to work without them. I had an extra fuel gauge luckily because the one in the car didn't work right.
 

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Finished my front suspension. Ran out of gas on my test drive!. Poured ten gallons in and the front end is excellent. I knew the gas level indication was bad but didn't think it was that low. I'll begin troubleshooting the gas gauge today and will let you know what I discover. If you have already diagnosed and solved your indication please reply. I'll do the same. Thanks.
 

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Eurica!!! thanks galaxiex !! Used your img016.jpg you had posted to bama64 and am another step closer to diagnosing the problems with my fuel level gauge. I bypassed the test with the gauge proper because I already knew it would indicate due to the probs with the CVR which I replaced. I went to the test with the circuitry from the sending unit to the gauge. Gauge responded. Now I know, without a doubt, that the gauge and circuit is good and the problem is with the sending unit. As my budget allows I'll get a new sending unit and most likely a new tank as well. Thanks again. I'm 65 yrs old but never to old to learn something new even it is from an old manual. Where can I get one?
 

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Eurica!!! thanks galaxiex !! Used your img016.jpg you had posted to bama64 and am another step closer to diagnosing the problems with my fuel level gauge. I bypassed the test with the gauge proper because I already knew it would indicate due to the probs with the CVR which I replaced. I went to the test with the circuitry from the sending unit to the gauge. Gauge responded. Now I know, without a doubt, that the gauge and circuit is good and the problem is with the sending unit. As my budget allows I'll get a new sending unit and most likely a new tank as well. Thanks again. I'm 65 yrs old but never to old to learn something new even it is from an old manual. Where can I get one?
An old Motor Manual?

Hmmmm, could try a antique/used book store.
Possibly ebay too.

I've had mine since the 70's.

There is also this site...

http://www.oldcarmanualproject.com/
 

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Thanks again! Ordered a new sending unit this pm. The tank will have to wait. Your moniker suggests you're a galaxie owner. I never had one but have always wanted one. My experience has been with the Falcons, Fairlanes and English sports cars. Keep posting the advice.
 

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Cant remember if I responded or not. Got a new 14 gal fuel tank and sending unit from FalconParts.com. Now I got two new sending units but thats OK. Waitin on the weather to cooperate before I paint and install. Like you say, the calibration is another question all together but any indication is better than none at all. My speeddo and mileometer/tripometer still works so I think I can estimate if all else fails. Even if I run outta gas again it's better than not havin the car at all. Does any body still use this forum?? Not to many like minded folk around as far as the Falcons are concerned.
 

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New tank and sending unit complete. Filled tank 5 gals at a time and verified the gauge is responding and capacity correct. finally filled the tank to overflowing and gauge shows just better than 3/4 full. Well its better than nothing. Calibration is off but I'm gonna go with it. Next step is to get it on the road and estimate the MPG. Starting on a new exhaust next. The full length headers I'm runnin now ( manufactor un known) create too much interference with the power steering crap etc.. Any recommendations on shortys? May end up going with stock manifolds. Also still runnin old glass-pac ( cheery bomb) mufflers but thinking about flowmaster series 40. What are yall runnin?
 

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Still chasing fuel level indication. GalaxieX mentioned calibration.I should have listened. If anyone is still out there, what is the proper procedure for calibration. I'm sure the gauge and sending unit are in order but can't get a true reading. I'm inclined to believe I have a 14 gal tank but using a 16 gal sending unit. I have a spare new sending unit that was sold to be a 14 gal unit. Before I drain the tank and replace the sending unit ,I need to know if there is something I'm missing in regards to calibration. Please respond.
 

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Don't know if you have a shop manual.. but the info is in there.

This is from my 68 Mustang shop manual.
All gauges work the same in 60's Fords.

May have to read thru these a few times to figure it out....

164606



164607


164608


164609
 

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Thanks Again GalaxieX!!!!!!, wish we were neighbors. I do have a work shop manual, but it is not as specific or descriptive as the info you posted. After performing the tests I'm almost certain the gauge is at fault. It moves but I don't think it is capable of reaching the FULL mark. I tested it using a new sending unit and it still will not register full. However when I tap on or around the instrument the indication will jump and climb toward full. Thanks again for the info. Can't complain. The gauge has seen it better days since 1964. Me too I guess.
 
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