gas gauge madness

Woodie UK

Woodie UK

Member
The gas gauge in my newly restored '36 woodie has not worked properly since I put the car back on the road a couple of weeks back.

I've put in a new Bob Drake generic sender unit and a voltage reducer on the gas gauge to drop it from 12v down to 6v.

As soon as I turn the ignition on the guage goes off the scale to full and never moves. Now the needle stays right up the top whether the power is on or off.

I've got power at the sender unit and at the guage and I'm beginiing to think the guage is faulty.

Anybody ever had a similar problem??

Colin
 
If the new sender is a variable resistor type then it won't function the old heated bi-metalic strip type gauge unit correctly. You will need to find a working original type sender or find a rebuildable core, otherwise you will have to get the gauge converted to a resistance type unit to mach the resistance of the available repro sender like you have.

Kerby
 
Had my original 36 guage (dual Oil/Fuel)calibrated and converted to 12V by Lee Kelly in Idaho.Ford guages are actually 5V according to him.I used the Drake sender .Works perfectly.(leebobk@cableone.net)
 
A variable resistance unit will work if calibrated properly.

When you say you put in a generic sender, you'd need to know if it was for your car or not. Bob Drake does sell senders for the early Fords - I prefer the 6V ones then drop the voltage down with a CVR rather than a 12V one (which Drake also sells).

There are those who will argue with me, and there were a couple of spirited debates/disagreements on the old Barn, but it works just fine on my two converted vehicles. In fact, I would argue that due to the CVR being in the circuit now, mine are more accurate after the conversion than prior to it.
 
I had problems with my gas gauge (always read F), and found that my problem was a bent float shaft, which I corrected. However, in doing some research, I found that there are a variety of senders with different resistance ratings. The sender must be matched to the meter (or visa versa). I don't know if there is such a thing as a "universal sender". I am using after market items, so it was easy for me to just check via the part numbers.

I'm afraid that, with the needle always pointing to "F", even with no power, that the meter may now be defective. As a minimum, it has been jammed to the upper stops and will need to be nudged back somehow (not electrically).
 
Joe/Ct said:
I'm afraid that, with the needle always pointing to "F", even with no power, that the meter may now be defective. As a minimum, it has been jammed to the upper stops and will need to be nudged back somehow (not electrically).
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I know many of the stock gauges have a tiny gear train in them - if you remove the gauge and the paper/cardboard back held on by the nuts very carefully, you will see two holes and you can access the gears in there - this is sometimes used to adjust a gauge, but might be used to free up a gauge that is stuck.

I believe, but do not know for sure, that if the original poster had burned the gauge out it would read empty all the time...
 
Colin,
My 47 always had an inaccurate gas gauge, so I bought a new sender because they said it would work with 6 or 12 volts. It made my gauge go to full, or beyond. As you know there is no returning electrical parts, so I hung it on the wall with all the other stuff. Just out of curiosity I prided the top of my original sender to see how it worked. It sounded like I just opened a beer, the 60+ year old seal had done it's job so well that there was a vacumn inside that prevented the bellows from moving. When I hooked it back up to the car for a test it worked perfectly at all levels. My car is 12 volts with a reducer for the gauges. It made my day that the old one worked so well, Chuck.
 
I'm bringing this thread back up top. I've got almost the opposite problem. New so-called "universal" 6v-12v sender from Mac's, original '41 ford gauge with a 12v to 6v reducer. When the arm on the sender is all the way up (full position) the gauge only reads just below half tank. All the way down, it reads right at the E line on the gauge. Makes me think that the sender is too high of a resistance for the gauge. The oil pressure and temp gauges work fine so I know it's not a voltage supply problem.
 
52merc said:
chuck how easy was it to pry the sender unit open
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19Fordy reply: I was able to gently pry the top off my 1940 Ford sender unit using a brake adjusting tool. Works great with no damage. Maybe it will work for you.
 
My guess is you have a short in your wiring? Try to hook a jumper wire from gauge to sender and try it make sure you ground the sender.
 
Not sure if you're responding to me or not, but... Sender is securely grounded. When the sending wire is grounded, the gauge moves all the way to the full side. Wiring is all new, no shorts.

I guess it's gotta be that stupid repop sender! WTF! :mad::mad::mad:

I'll see what the resistance is when it's in the full position. I'm going to guess it's supposed to be pretty near zero and for some reason or another (probably cause it's made in zimbabwe or something...) it's not.



BOSSY said:
My guess is you have a short in your wiring? Try to hook a jumper wire from gauge to sender and try it make sure you ground the sender.
Click to expand...
 
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