Fuel tank sending unit for 1946

Jim Kilday

Does anyone know if the unit sold by Dennis Carpenter for Ford products will work in my '46?

Has anyone tried the ones from Atwater Kent. As I recall they are very pricey.

http://atwaterkentmfg.com/Fuel Senders.htm

Park_W

Jim, I have one of the Carpenter units in my '47, and it works pretty well, though not perfectly. I guess one could describe it as having a little wider range than the original unit (it's a pure resistive sender vs. the thermal make-and-break design of the original). I had to play with the setting a bit to get the operating range "centered" on the gauge. Given the price of having the original King-Seely unit rebuilt or replaced with a new one, the Carpenter sender is a resonable alternative.

Jim Kilday

Park W wrote:

Jim, I have one of the Carpenter units in my '47, and it works pretty well, though not perfectly. I guess one could describe it as having a little wider range than the original unit (it's a pure resistive sender vs. the thermal make-and-break design of the original). I had to play with the setting a bit to get the operating range "centered" on the gauge. Given the price of having the original King-Seely unit rebuilt or replaced with a new one, the Carpenter sender is a resonable alternative.

I'm a real novice at this stuff. What do you mean when you say you had to play with the setting? Is this at the guage or the unit. It would be helpful if you could elaborate on this a bit.

Thank you,

JKilday

brumac

Jim,
The Carpenter unit in my '54 works well. I set it uo to read 'E' with an empty tank. At 1/2 on my gauge there is 10 gallons in the tank (which is 1/2 full for my 20 gal tank) A full tank reads 'F' and that's good enough for me. It does work well.

Bruce

Park_W

JIm, I was referring to playing with the amount of bend in the heavy wire float arm, which determines the gauge reading for a given float level. If the float hangs too low (as you're holding it, outside of the tank)the gauge will read too high ... it'll stay on full for a long time and will still be reading something when you run out of gas. Too far the other way and it reads a little low when the tank is full, and reads empty prematurely.

I'm afraid I have to disagree with the above post on the Atwater Kent units. I believe they're built internally like the original King Seely units, with a heater element and a bimetallic strip with a set of contact points. The objective of that design was to minimize the effect of varying voltage on the gauge reading.

Jim Kilday

Thanks for all the input. I ordered a unit from Carpenter.

JKilday

LanceB

Is there a way to apply voltage and a meter to bench test a sending unit without placing it in the tank?

[Deleted User]

Sure, I do it all the time. just need a 6- volt batery and an extra dash
gauge assembly. Hook it up the way your wiring diagram shows or use the
service manual diagrams. When moving the float keep inmind there is a
slight time delay. A dampening effect to keep the needle from jumping around.
I usualy do it on the bench and clamp the sensor assy. in a vise so I don't need to hold it.
Roger

[Deleted User]

I guess I should have mentioned that an ohm meter could tell you
a lot about the sending unit. It is basicly a variable resistor
and will change readings as arm is moved. It will be low readings
You will need to look at your manual.As I recal it would go from
60-120 ohm or something like that. If you old one gives a steady
reading as arm is moved I would say it was good.
Roger

brumac

When I installed my Carpenter unit I had my tank out and sitting on saw horses which were level. The sending unit was commected to the car's wiring with test leads. The tank was empty and I bent the float arm so that the gauge in the car would read 'E' with the sending unit installed in the tank. The pointer was just at the low edge of the gauges 'E' mark. I poured in 3 gallons of gas and the gauge read just above 'E'. This is nice to know!!! You will have to allow time for the gauge to settle down and not move. Now, a full tank reads at 'F' and at 1/2 the tank will take on 10 gallons.

Good Luck,
Bruce

LanceB

Thanks guys, I will give that setup a try.

Park_W

Roger, for the record, what you described applies only for the '51 and later Hudsons. The earlier sending units were not variable resistors. They work via a bimetallic strip and heater element, and there's a similar element in the dash gauge. An ohmmeter will show zero (a dead short) on these units. That said, the resistor type replacement from Carpenter does work pretty well as a substitute, even though the operating principle is different.

Park_W

LanceB, you can also do the sending unit check using the gauge in the dash. Use a jumper wire to extend the sending unit wire (the one that connects to the sending unit)out from under the car, connect it to the sending unit and use another jumper to ground the sending unit case to the car. Then turn the ignition on, and you can see the dash gauge reading for any particular sending unit float arm position. Of course this method is only useful when you know the dash gauge is good, such as when checking or calibrating a replacement sending unit.