Have a 57 bird. 

Put in new sending unit, gauge only reads 3/4 full. 

When tank is empty, the guage reads 1/2 full. 

Tried an after-market Ford fuel gauge and when hooked up it only pulsated. (is that a clue?)

Disconnected the sending unit wire (yellow) and grounded it.  The fuel gauge pegged full.  re-attached wire to sending unit then clamped onto the locking ring and grounded it.  Gauge only read 3/4 full.

I pulled the sending unit out, grounded it, and turned key on.  As I moved the sending unit, the gauge dropped but never went to EMPTY.  All the way to the top and it never read full, just a hair over the 3/4 mark. (sending unit the problem?)

This is the second sending unit from Concours.

Does the direction the sending unit faces in the tank matter?  Currently facing towards the front of the car.

Any other possibilities?  I see there is a voltage regulator that both the fuel and temp gauge connect to behind the dash.  Could that be bad?  Temp gauge reads hot even when it is not actually running that hot. 

If it is the regulator, any idea where I could find one?  None of the T-bird books have them.

Sorry for all the questions.  Thank you for your help.

1957 Thunderbird

312

You can check the regulator and see what voltage is coming out of it.  Typically they run about 5v.  As long as the voltage is steady.  I had one fail on my 62 F100 and I bought one from NAPA.  Those electrical parts should be available.  Typically it is a very inexpensive part.  At first when you were describing your issue I thought maybe you had a bad ground.  When you mentioned that your temp gauge also is not working it sounds more like the regulator.  My guess is that it is shorting out inside and asorbing all you voltage.  Eventually it will most likely get so hot you will smell it and it will melt.  That is what happend to mine.  Good luck.

Robi

The original ones were basically a set of points that open and close so the average voltage was 6 output.Most of the regular suppliers of vintage Ford parts sell them and as I understand it some of the new one are solid state electrical-no points.As suggested check yours for output voltage.Interestingly 1956 was the only year that the gauges used straight 12 volts-no regulator.Right through the late 60's early 70's most Fords used the little regulator on the backside of dash to supply 6 volts to gauges.

  

I ordered a steering wheel pull and dash removal DVD so I can figure out how to get the cluster out.  Not much of a contorsionist, so if I can pull out then I can check.  Found the regulator at CASCO for $80 (**OUCH**)

I will be back with an update.  Thank you for helping me out.

Rod

1957 Thunderbird

312

Can anyone tell me where to find the regulator for the fuel/temp? I thought it was mounted on the back of the gauge cluster but after a bit of twisting I could not see one. Just a round unit, about the size of a film canister that I think is the blinker control but not sure.



Thanks



R

1957 Thunderbird

312