[BDK]

OK Folks
My gas guage isn't working quite well. I top off the tank and it will show just passed the half way mark on my guage. I swapped out my tank and float in the past month and still the same issue as before. I checked the connections and everything seems OK. Do you see the actual guages going faulty on these? Any ideas?

Thanks

Mike

[mustanggarage]

the gas gauge in a 65 works by applying voltage to the gauge and then a modulated ground through the sender. just take the wire that goes to the sending unit and ground it. if the gauge goes all the way to full then the gauge is ok. if it still goes only halfway check to make sure it is not a mechanical issue like a bent needle. when you say you replaced the float did you replace the whole sending unit?

I borrowed this information from a guy I trust on another forum. I am not to hot with a multimeter but this is what he says.

The voltage ACROSS the gauge, not the voltage from either terminal to ground, at different tank levels (in gallons) should be roughly (calculated assuming a 6V CVR):

1.5 gal 1.1V (lowest sender will read)
2.5 gal 1.3V (indicates 'E' - Henry didn't want you to run out of gas )
5.25 gal 2.27V (indicates 1/4)
8 gal 2.57V (indicates close to 1/2 - first to be close to correct)
12 gal 3.27V (indicates 3/4 - what luck, another one is correct!)
14.5 gal 3.72V (indicates Full)
15 gal 3.79V (Above 'F', highest sender will read)
16 gal 3.79V (Tank actually full)

[mustanggarage]

btw my guess is that your problem is still in the sender. the gauges can go bad but it is much more common for these reproduction senders to be bad out of the box.

[MustangOne]

The easiest way to check is to take the wire from the sending unit.

With the key to on, Ground it to any metal under the car.

It should sweep to full, If it does the float has fluid in it.

If it only goes to half it is the gauge.

[BDK]

Well i just grounded it out and it went full. Guess i need to swap out the float. Thank You very much for your help!

[mustanggarage]

Originally Posted by BDK Well i just grounded it out and it went full. Guess i need to swap out the float. Thank You very much for your help!

check the float and see if it has fluid. it may, but what can also happen is the rheostat in the sender can be not making contact all the way. so you would need to replace the complete sender. like I said some of these reproduction senders just aren't much good.