Temp and fuel gauge guts the same?

[Robj]

You use the same tester to test both temp gauges cold, middle and hot and and fuel gauges empty, half and full. They both react the same to the same ground resistance? It seems that other than the fact that the terminals on the back are mirrored, the mechanical innards should be the same? An unused good temp gauge could be used to replace a fuel gauge if you rewired and mirrored it to the terminals on the back? I searched the forums and didn't see anything but I'm sure it's been discussed and questioned before.

added- 70 Dart -standard dash.

 

[1969383S]

Not if the regulator is in the fuel gauge.
What exactly are you working on or considering?

Ok 70 Dart, ralley?

 

[ddartdude]

Not if the regulator is in the fuel gauge.
What exactly are you working on or considering?

Ok 70 Dart, ralley?

Yes.

 

[RedFish]

You use the same tester to test both temp gauges cold, middle and hot and and fuel gauges empty, half and full. They both react the same to the same ground resistance? It seems that other than the fact that the terminals on the back are mirrored, the mechanical innards should be the same? An unused good temp gauge could be used to replace a fuel gauge if you rewired and mirrored it to the terminals on the back? I searched the forums and didn't see anything but I'm sure it's been discussed and questioned before.

added- 70 Dart -standard dash.

Wouldn't that be great? Sorry but no. Its the mechanical design that makes needle travel left to right or vise versa. Electrical current generates heat which bows a piece of bi-metal and causes needle movement. Switching the current poles +/- would not cause that bi-metal to bow in the opposite direction.
I do know of one example where after the first year of production, Their engineers figured out that the oil and temp screens could be placed on the same instrument, and they did just that. The folks at S/W tweaked the heck out of the mechanical adjustments and needle stops to make it work but... It worked.
So edited to read standard panel. That means I have to edit my post too. Let's say you do have square temp and fuel gauges. Both needles travel left to right. Still no need to switch polarity but... I'm pretty sure you will find the temp gauge reads approx' 20 ohms post to post. The fuel gauge reads approx' 13 ohms post to post. So how they react to the supplied current is different.
I honestly don't know if that temp gauge can be a somewhat accurate fuel gauge.
Majority of my experience is in the round pod rally gauges. I found the engineering in those gauges mind blowing. Even though 23 ohms would hit very near the center of all 3 ranges/screens, values like 34 ohms, 62 ohms, etc.., is different in all 3.