The float in the tanks is a brass ball that is clam sleaved together with swet solder. The solder joint has failed and the float ball has filled up with gas and thus sunk which does not enable the gauge to work (always shows empty). Remove the gauge from the tank top, snap off the brass ball and re-solder the seam. CAUTION: THE BALL IS FILLED WITH GAS AND ANY SOLDERING HEAT OR FLAME WILL CAUSE IT TO BLOW UP AND CATCH FIRE. What I had done was to drill a hole in both ends of the ball float, drain the fuel, fill with water and blow the water out, then re-solder. Despite the water wash, the brass will still be impregnated with gasoline, so a small explosion, however manageable, will still occur.

Best Birding,
Jed Zimmerman
58ht in MN

"Grounding the sender wire does not move gauge" is a very valuable start!

Does your temp gauge work?? They run off of the same 6v source (the little "voltage regulator" bolted to the back of your instrument panel)

If Yes then it sounds like the gas gauge itself is an open circuit. First I would make sure the
leads to the gauge were on it properly.

But I would also make sure the wire from the gauge to the trunk was not broken/open. I own a long pair of homemade jumpers for such tests. I assume you have a multimeter - all you need is resistance.

The gauge is easy to remove from the dash to work on - the bezel pulls off and the gauge is held on by 3 or 4 little Phillips screws. Make notes of what wire goes to what post. With the gauge dangling out in the open you can then use jumpers to ground it out, check for voltage to it, look for wires off and so on.

Worse case scenario: no continuity across the gauge. Then it is dead. Personally I would get another one on Ebay (59 and 60 both had white faces while 58 is black) although there are gauge guys out there who overhall these things (see Services in Hemmings)

At the trunk end, the unit needs to be grounded out properly to work and paint/rust/crap can prevent this. Five minutes of cleaning can fix this. As Jed says, its gotta float!

Basic attitude: take nothing for granted.

Basic goal: keep narrowing it down. Keep us posted!

John

Also check the ground wire at the sending unit.

Gas gauge

Guys, mine reads full when ignition is on. Temp gauge works fine. I have checked everything except sending unit. Any suggestions?

you mean Full but the tank is not really full??

I would want to take the sending unit out and see if it is physically moving for starters... or damaged in some way...it is very easy to get to via your trunk. If the sending unit is shorted out then your gauge would indeed read Full.

59 gas gauge

I think a new gauge is the best option. I have the gauge into the folks to repair it and still nothing. It reads empty all the time.

you have several components to the system. You really need to get a multimeter, look at the wiring diagram for the circuit , and narrow down the failure.

Specifically you have a 6V voltage source on the back of the instrument panel, the gauge, the sending unit in the tank, the wiring between all parts , and last but not least, the ground.

Gas gauge

Thanks John!
I will try this and see what I can figure out.

I was doing some work and thinking about a logical approach to it. Here's what I came up with:

1) is your Temp gauge working properly? If Yes then this means your 6V regulator probably works fine. If No then check that (see 2) below )

2) (independently) Put the DC voltage part of your meter on the output of the 6V regulator on the back of the dash (I want to say the wires are Green but you should check the wiring diagram). You should see it fluctate as it is going On and Off with the average being 6V (as your car is 12V).

If it is 0 volts all the time it is dead. Buy a new one

If it is 12V all the time it is stuck and also needs replacing. It will fry your gauges if not replaced.

3) Assuming the 6V power source is OK then move to your gauge. Disconnect the lead that goes to the sending unit (again see Wiring Diagram for colors). Briefly ground the post on the gauge out (with the key on Accessories) and see if the gauge jumps up to Full. If Yes then your gauge is probably fine. If No it is dead.


Wire things up as they were and move on...

4) Assuming your gauge is OK then move to the trunk and move the floor mat off the sending unit. Disconnect the lead to the sending unit and, with the key On, again ground out the lead to the sending unit. It should cause the gauge to jump up to Full. If not then the wire from the gauge to the sending unit is bad (broken) and needs replacing.

5) If step #4 went ok then move on to checking the sending unit.

a) remove it by rotating the retaining ring

b) cover the opening with rags and be very careful!

c) clean up the area where it grounds out to the body (paint, rust and goop may be found)

d) put your multimeter across it with the meter in Resistance mode and see if it has continuity. By "across it" I mean with one lead on the post the wire hooks to and the other on the metal cover (which is ground). Try different resistance scales. If it always shows an infinite number of ohms you have an Open circuit and the sending unit needs to be repaired or replaced.

e) if it does show resistance then you can simulate its action by reconnecting the lead from the car to its post and putting a jumper to its metal body and to the body of the car. (keeping away from the gas tank and still having the opening of the tank covered up for safety sake). Turn the key to Accessory and move the float arm around and you should see the gauge move back and forth from Empty to Full.

Now somewhere in all this, a step should fail and you can identify the bady component or lack of ground. But it is a linear circuit and by moving from front to back you should be able to identify your problem.

Please let us know what you find!

Once you get it working you can calibrate the gauge with instructions that Alexander on this site.

John

1960 Sending unit

Hey Guys,
I took my sending unit out today. Made up grounding wire with terminals on end for grounding, turned key to on and worked unit. It would try to read but was sluggish. I took it apart and spring sensor was messed up. I am in process of trying to get new one. My question is is fuel filter at carburetor the only filter on 1960 Thunderbird or is there one in tank?

gauge: you could buy another one on Ebay for cheap and either steal parts or swap.

filters: there is one in the tank. If you search old threads, someone took a photo of a tank cut up in a junkyard and showed it. Does not seem to be removable. I drained my tank and blew out the filter with carb cleaner.

john

59 Gas Gauge

Bird Nest has the Fuel Tank Sending Unit A4-25 For $69.95. Fits the '58-'60 Tbirds gas tank. That is where I got mine from. 800-232-6378. I am sure the other Tbird parts places have them also.

Gas tank filter

THANKS GUYS!
I found one on Ebay for fourty dollars plus shipping. I have sent sells person question if it was new or not. I also noticed he had several.
I had carberator rebuilt last year by company in Texas. He told me carb. was a mess. I still have some hesitation right at take off. Could filter in tank be clogged or do I have fuel pump issues?

did you find a Sending Unit or Gas Gauge on Ebay for $40 ??

There are a ton of possible causes of hesitation...