I just used basic electrical formula.
Original sender had simple resistance wire and new one works same way.
It costs nothing to test.
I also got diy adjustable voltage converters for gas- and temp gauges so that might help too.
But yes, you might be right, usually my projects go south...


Hyvinkää, FI

Does this mean that the same sender(556FS) will work equally well with the 1955 6-volt positive ground and the 1956 12-volt negative ground with no modifications of any sort? Just install it on either one right out of the box? I am referring to the post from Brent yesterday.

JLB,
I scoured and used electrical cleaner, now my meter is measuring resistance. the readings are jumping around sporadically,  similar to the replacement I purchased from Hill's. Is this an example of "floating ohm range?"




.150 Stroked Y-Block:327.25 ci @ >1hp per ci
 

Brent,

Something's still wrong: My best guess (by remote troubleshooting - which is never a great thing) is that you're still getting intermittent connections with your meter (still likely - can probably be corrected by solid screw connections between sender and meter leads); or, some internal connection is corroded/points burned.  After all, these are many decades old and in a hostile environment both in and out of the gas tank. Seals and/or diaphragm may have deteriorated to the point of letting moisture/gasoline inside the electrical workings.

Try making solid meter to sender connections (screw/bolt them down tightly); then, try moving the float through its range and see whether the resistance stays relatively steady (which it should, + or - a few ohms); or, if the resistance measurement wanders/spikes around all over the place (a serious indication of corrosion/points burned).

If it still indicates problems, there's no loss in opening it up for curiosity's sake. I've only opened the engine temperature sensor and never have done the fuel sensor: If you can carefully open it up, you may be able to clean the points and see what else may be going on; and, put it back together - as a possibility. If you decide to do so, please take good pix and share them with us as to what you found.

If it tests "good" with solid connections; then, I'd advise going through every electrical connection in that circuit and clean/re-tighten each (and use some [minimal] "no-ox" on all screws/connections). The "no-ox" is good for the sender-to-tank mounting screws also: It will help slow-down/prevent future corrosion.  I know that it's messy; but, it'll really help in the long-run; just keep "shop-rags" handy.

Good luck, JLB

55 Ford Crown Victoria Steel Top

I installed the matching fuel gauge and sending unit kit in my 55 Thunderbird today. It works on resistance.  It still needs a little adjustment as it reads low.  Better than running out of gas.  The gauge moves around a bit when the car is moving.  I'm pretty sure it did that when the car was new. 

Brent

I received the Summit fuel sender today  https://www.summitracing.com/parts/tnk-556fs

A few quick notes first. I mounted it in a wood test mount so I could get more accurate readings than holding the thing in my hand and holding test probes while moving the float up and down. I also connected the Ohm Meter leads using ring terminals so intermitent connections would not skew the readings.

First test resulted in "0" ohms full and empty, Looking around the sender I found that the connection stud had a lump of solder that was touching the case. I found that loosing the jamb nut and rotating the stud it would clear the case (dont go to far or you will break the wire that the solder is attaching)

Now that I have repaired my brand new sender here are the results              Full  -  35 Ohms                  1/2  -  131 Ohms           Empty  -    266 Ohms

Using the Digital meter the readings were very jumpy,  The analog meter read smoother but did jump in certain spots around 1/2 tank.  I am thinking that the resistance element may have some kind of oil on it that installation in a real gas tank would wash off and smooth out the operation. 

If I get time over the weekend I am going to take it out to the car, remove the sender wire from the gauge and wire and ground the new sender out of the tank and see how it works on an actual gauge

Will report back

The specs are real close to the “aftermarket” sensors, 240/33Ω.I’m going to say, ‘when’ your new sensor works it’s going to present a whole new twist. Hmm…Thanks for the info!

.150 Stroked Y-Block:327.25 ci @ >1hp per ci
 

Just really curious; any update?

Regards, JLB

55 Ford Crown Victoria Steel Top

No updates yet, it was 11 degrees here most of the weekend, to cold to work in the garage.  They are saying warmer at the end of the week, hope to get to it soon.

Thanks for the update.

Oh, come on - that's not cold - LOL: Your +11 o F temp. is in the tropics - we're going into -24 actual air temp coming Thurs. - Fri.  And - years ago now - I actually replaced Y-block rings and main bearings outside in -35 air temp weather: Young family and no choice on the weekend to be ready for Monday's work schedule. Years later in early Feb. of 1996 got called-in to work at my electrical utility power plant for cold-weather problems on my scheduled day off - arrived to find actual recorded air temp. at -65 on our calibrated weather station at 08:30 CST - was "outside" work; now THAT was cold! "Official" recorded temp. for MN that day was -54 - the thermometer actually broke at the NWS measuring site, so could not measure "actual".

Still really looking forward to your information as to success of "new" fuel sender working with original gauge.

Regards, JLB

55 Ford Crown Victoria Steel Top