If your dash guage is still original equipment, it is not at all compatible with any other sending units - ONLY the original-design King Seeley for Ford will work ('54 & '55 are specifically for 6V,; and '56 is specifically for 12V - they are not interchangeable).

It's a "different" bi-metal & heater coil arrangement at both the sender and at the guage and will not work with resistance-type sending units.  They actually work quite well when all the wiring (grounds, etc.) is clean and good; AND operated on the proper voltage system (a 6V system will work for a while on a 12V conversion; but, will eventually "burn-out").

Both the fuel guage and Temperature guage circuits are of the same basic design and not compatible with any other design type.

Hope this helps you.

Regards,   JLB

55 Ford Crown Victoria Steel Top

Mike;

I ran into this problem when I replaced all my guages with Haneline guages. I had to use their (universal) sending unit that you cut to fit the depth of your tank. The stock Ford sending unit wouls not work with the new guage.

Rono

  Ron Lane,  Meridian, ID

now I have the original gauge but I feel it's bad and maybe the sending unit also, looking to replace with an after market gauge but don't know if I can adapt an after market gauge due to the ohm difference in the gauge and the sending unit.

Claim to fame is the car was used as an extra in the movie Diner with Micky Rourke, Steve Gootenburg, Paul Riser and Kevin Bacon.

Mike;

Do you have the original, factory gas guage or is it an aftermarket guage?

Rono

  Ron Lane,  Meridian, ID

I would but it's the same unit at Tee-Bird that Mac sells, Mac has it listed as a 6/12 but the 12 is a mistake, not my wiring. I by-passed the wiring and went to the battery, the gauge and then to the sending unit and still pegs the gauge but I have the old dending unit in, I'll try the new one again tomorrow and if it doesn't work then it's my gauge.

Claim to fame is the car was used as an extra in the movie Diner with Micky Rourke, Steve Gootenburg, Paul Riser and Kevin Bacon.

Interesting that Macs uses same unit for 6 and 12 volt.Tee-Bird.com uses different senders for 55(6 volt) and 56 (12 Volt).If it doesnt work properly and you cant get proper asistance from Macs,send it back and go elsewhere I would suggest!.They charge enough for the product,At the very least they should give proper customer sevice when there is a problem.Maybe they have gotten too big and dont look after their customers like they should?

  

My gas gauge wasn't reading correctly so all test indicated it was the sending unit, I purchased a 6/12volt unit from mac's, when I power it up the mac unit , the meter pegs.

Mac tech service said I had a ground in my wiring.

If I have a ground why didn't my old sending unit peg the meter ?. also does the ohms make a difference in these units?, my old unit spec ia 18 to 24 ohms  , not sure what the new unit is but the tech guy at mac seemed to be more interested in getting me off the phone , I don't think he knows anymore about cars than I do.

I would appreciate your comments.

Thanks,

Mike

Claim to fame is the car was used as an extra in the movie Diner with Micky Rourke, Steve Gootenburg, Paul Riser and Kevin Bacon.