thanks for help me
the car is come from ontario maybe it's different in usa ?
do you think if i buy 57 t bird (the small) and it works with my 56 gauge ?
or i must change the gauge?
If the car was built in Canada, Yes the parts could easily be different than for cars built in the US.
It may(?) also make a difference if the car was built early or late in the model year. The Build Date should be on the data plate of the car. See this pdf link, that opens in a new window...
https://thecvaonline.com/howtos/DataPlateDecoder.pdf
Try to figure out what parts the car has in it now.... beginning with the engine or cylinder head (is it the original one for the car?)
Here's a link with ID info for the engine block...
http://www.ford-y-block.com/Block%20identification.htm
and the heads...
http://www.ford-y-block.com/cylinderheadchart.htm
Determining if the car uses a '56 or '57 style wiring setup may be slightly difficult, and it makes a notable difference.
Look at the back side of the dash board and try to locate a voltage regulator that may or may not be there. (example image below)
If the car has one it will be located specifically / only in the power wiring to the Fuel & Temp gauges, and possibly screwed to the back of the dash gauge cluster.
Don't be distracted by the similar looking Circuit Breakers that are located in the larger size (usually yellow) main power wires.
Also look on the back side of the temp gauge you have for the date it was built. A slight problem is, both a '56 and '57 gauge will be marked "12v", so a date is more important.
What is the "easiest" way to fix your Temp gauge problem???
Did you test the gauge by temporarily *grounding* the sensor wire to the engine or other metal of the car? (with the ign key turned on) The gauge needle should move all the way across the dial if is working correctly. If it doesn't the gauge is bad or receiving no power from the Ign key switch.
You should be able to test the temp sensor with an Ohm meter. With the engine cold and the wire to the gauge removed, it will show a specific resistance. With the engine at operating temperature the resistance will be different. (I don't know any actual resistance readings)
If the sensor is out of the engine you can still test it cold/hot with an Ohm meter and a pot of boiling water, but don't burn your fingers. Also, don't put the entire sensor into water, just the end that goes inside the head.
After some trouble shooting... since you may need to replace some parts to get the Temp gauge working...
I'll suggest that due to the tools needed, it will be easier to change - a sensor, regulator or gauge, but only 'as needed' and after locating the underlying problem.
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