Adjusting Fuel gauge

[KramNation]

Hello all,

I have a 65 mustang I'm repaing. I have replaced the sending unit, but my gauge only moves to under a 1/4 on the gauge when I fill up. I could could bend the float on the sending unit to adjust it, but how about adjusting/Replacing the constant voltage? Also, the temp gauge goes off the voltage unit too and it does not read either. I was going to by a new temp sending unit, but maybe the consatnt voltage is the problem.

Questions are:
What is the correct voltage for the constant voltage unit?
Can it be adjusted?
Would this cause it to read just a little, or would it be it either works or not works?
Is adjusting the float on the sending unit the way to adjust.

Thanks for any help.

 

[my66coupe]

Im not 100% positive on voltage but I think its around 6 for the guages. The constant voltage regulator would throw it off for sure. If the sending units are bad then yes it can as well throw the reading off.Normally if the sending units are bad, you wont get any reading at all. Pop your wires off at the sending units, and ground the wire. if your guage pegs (to the right), then the wiring is good and your sending unit is bad. Make sure your ground strap from the firewall to your engine is attached and tight, that can throw the guages off. Good luck

Mike

 

[ForceFed70]

If the voltage regulator was bad, all of your guages would be reading funny... not just the fuel guage.

My guess is that the sender/tank is not properly grounded. Try running a wire directly from a good ground to the sending unit body and see if your guage starts reading properly.

 

[84convertablegt]

also, if your connector that hook up to the sending unit is going bad or corroded or your wiring is going bad, you will gain resistance in the wire which will act like the resistor in the sending unit itself, limiting the amount of ground getting back to the gauge and that will make your reading low. i had this problem, all i had to do was replace the connector with a spade terminal and added a nut to the sender stud to make a tight positive connection. problem solved.