'59 Plymouth Forum

I need a new fuel sending unit for my '59 Savoy. Are they available anywhere? Does anyone know the part number for this unit?

I haven't had any replies to my questions on my '59 Plymouth fuel sending unit. How about odds on repairing the existing unit? It seems to operate intermittenly when the tank is full down to 3/4 full. Perhaps the moving contact is not making contact with the coil when the fuel level falls to a certain point? Any thoughts or suggestions?

JT wrote:I haven't had any replies to my questions on my '59 Plymouth fuel sending unit. How about odds on repairing the existing unit? It seems to operate intermittenly when the tank is full down to 3/4 full. Perhaps the moving contact is not making contact with the coil when the fuel level falls to a certain point? Any thoughts or suggestions?

JT, what's the behavior of the gauge when the tank's not full? Does it drop to "E"? Then your supposition is a good one... I believe that when the float is at the top, the rheostat in the gauge is close to zero resistance, permitting more current to flow and the needle to peg at "F". Increased resistance as the float drops drifts the needle towards "E". But if you encounter a coating (varnish?) on the rheostat -- or, a break -- that opens the circuit, I would expect the needle to drop to "E" unexpectedly.

What's the harm in removing it, and having a look at it? Perhaps something obvious will present itself...

Dan

Thanks, Dan. Yes, it drops to "E". I'll be pulling it out this week and will check it with my ohmmeter. If it isn't repairable, I'd like to source a replacement, which was my initial query.

Joe T

Sorry I missed your request of Oct 3.
The part is listed as "Fuel Tank Gauge" in the Fuel Section of the 1959 Parts Book...p. 14-8.

The Part #s are:

1) for 20 gallon tank....1842 443
2) for 23 gallon tank....1842 433
The above are for sedans and hardtops... the wagons are different.
As for locating a NOS one, try the various NOS suppliers that advertise in Hemmings Motor News, WPC News, etc. I believe there are also people who re-condition them, but I do not have any contact info.
Take out the one you have and see if it can be cleaned and repaired.

Check your float to see that it isn't cracked and also make sure you have a good ground. Mine was acting erratically so I removed it and found the float was cracked. Replaced float and also attached a separate ground wire. Works perfect now. When you have tank off, its a good opportunity to give it a good coat of POR 15 and paint.

JT, the problem you have is most likely on the sending unit in the gas tank and not on the fuel indicator in the dash board. Nevertheless both units work together.

The fuel sending unit is basically a fine resistance wire wrapped around an isolated bar. A pointer slips up and down this bar (wire) as the gas goes down or the deposit is refilled again. The pointer has a physical contact with the wire and therefore the wire becomes thinner and thinner over the years. I also had a case where the pointer was broken.
The fact, that your unit works from “Full” to ¾ and then drops down to 0 shows, that this contact is interrupted at one point of the scale. If you remove your unit on the weekend, than take a closer look to the wire and pointer. A pocket lens will help, the wire is really thin. If it’s definitely the sending unit, I have a rebuilt one that is as good as a new one.
Yes, it is possible to repair this unit but it is really a game of patience and a real “finger breaker”.

Take care

Stefan