Topic: Fuel Gauge Woes


pauls36fordor    -- 07-24-2019 @ 1:45 PM
  As anyone run into this before? The fuel gauge on my 36 Ford was reading 1/4 when it was full and empty when it was empty. But it would drop to empty when it was still half full so I really never knew when it was actually empty. So I replaced the fuel gauge sending unit. Now when its full the needle goes past full and out of sight. This weekend I ran out of gas when the needle showed 3/4. I followed the instructions that came with the sending unit including to cut the float rod to the length in the instructions. My thinking is the rod is either too short or to long (leaning towards long) and so its not dropping like it should as the fuel level drops. Any suggestions or thoughts? Or could it be something totally different?


trjford8    -- 07-24-2019 @ 4:50 PM
  If you bought a new repo sender they are notorious for giving inaccurate readings. I would look for a good clean original sender and put it back in.


MG    -- 07-24-2019 @ 5:03 PM
  Do you still have your original sending unit? See this thread > https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=12402&keywords=fuel%20sending%20unit

BTW - This is the thread that you initiated back in Oct. 2018

This message was edited by MG on 7-24-19 @ 5:26 PM


fenbach    -- 07-24-2019 @ 7:17 PM
  try putting a resistor in line with the wire to the gauge. that worked for me [I have an after market sender], altho I've long since forgotten what size resistor I ended up with. maybe start with 100 ohms. you'll have to experiment which pretty much means taking the sender out. then, the gauge itself can be adjusted. again, you'll have to take it out. and figure out how the adjustments work. I've long since forgotten. except that they control the tension on the needle and the rest position of the needle, as I recall, not the current flow. but first of all, make sure the sender arm is free to move the full extent of its range. you can maybe tie a string to the float and run it thru a bolt hole?? you'll need to have an empty tank or replace the float with a weight. in the meantime, just fill up every 100 miles or so.


carcrazy    -- 07-24-2019 @ 7:26 PM
  One workaround for dealing with an unreliable fuel gauge is to keep a fuel log in the vehicle glove compartment. I use a small 3" x 5" memo book for this. When filling up the tank, record in the book: the date of the fill, the mileage listed on the odometer, the number of gallons purchased, and the price paid. You can always check this to determine when to buy gas so you don't run out. This also can be used to determine your fuel economy between fill ups.


pauls36fordor    -- 07-25-2019 @ 2:05 PM
  Thanks everyone.


fordv8j    -- 07-25-2019 @ 5:43 PM
  I also have those units in our 2 38s, can't believe them, when I fill up I set the tripmeter,then can tell when getting low


Grant    -- 07-27-2019 @ 5:22 AM
  Hi Paul. Was there a cover plate in the trunk floor of your '36 which allowed you to access the sending unit?


37RAGTOPMAN    -- 07-27-2019 @ 1:03 PM
  FUEL GAUGE WOES,
you can try this
you need to measure how deep your tank is, REMOVE sender, be care full with gas,
the sender should be adjusted so it works in that measurement boundary
not hitting the top of tank and not hitting the bottom
but just about.
you can make a mock up gas tank out of wood or metal, like a square frame, with that measurement, do this on the
outside of the car on a work bench, using long jumper wires,
mount the sender to the top and use jumper wires push the sender up and see if it reads full and let it go down and see if it reads empty, adjust by bending the rod,
I hope this is not too confusing tried my best, hope this helps, 37RAGTOPMAN
like someone said it is best if you get GENUINE Original FORD PARTS,. not this aftermarket c####
WORTH EVERY PENNY. they at least work,
Ford made the basic fuel tank sender for many years,, rods were different had to be shortened or added to, 1936 to I believe to 1955 ?


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Topic: https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=13093