Fuel Gauge Reads Backwards

[japollon]

I have the FFR vintage gauge set in the 289 FIA. It seems that that the fuel gauge is reading backward. So when the tank is a quarter full, the gauge reads three quarters. When full, the gauge reads empty.

Thoughts? Help!!

[edwardb]

Obvious question first. Is it calibrated for your sending unit? The typical Mustang style sending unit FF provides should be calibrated for the 16-158 ohms setting (7/8 tank when in calibration mode). The factory default 240-33 ohms would make it read backwards.

[japollon]

i do not know the answer to this question Edwardb. I will put my ohm meter on it this morning to try and assess where it is in terms of calibration. If it is in fact wrong, what is the solution? New sending unit?

Thanks

[mike223]

It depends on what gauge package you bought from FFR.

If it's one of the Speedhut gauge options, you need to calibrate the gauge for the sender you have using the instructions here:
https://www.speedhut.com/instruction...structions.pdf

If you bought the Autometer gauge package, someone else will have to answer.

[edwardb]

FFR vintage gauge set is Speedhut. Use the instructions included and linked to calibrate. Unless it's defective (possible, but I doubt it...) you don't need to change the sending unit. You will also find the tach may need calibration. I'm guessing you have the GPS speedo, so nothing to do there. But if it's the style speedo with a vehicle speed sensor (VSS) than it will need calibration as well. All explained in the instructions. In your gauge box you should have a cord with a mini-plug on one end and a momentary pushbutton switch on the other. That's the cable you plug into the back of the respective gauges for calibration.

[japollon]

Got it! Thank you so much! Joel