Hello everyone,

I have aftermarket Auto Meter Phantom gauges in my 67

The fuel gauge reading is not accurate and I am looking for a way to calibrate it

When the tank is full the gauge is pegged . . .even past Full

When I am on fumes the gauge waves between 1/2 and 3/4

When I rebuilt the car a few years back I installed a new fuel tank sending unit, locking ring and seal, sending unit filter and wire. I did not change any of the dash or console wiring harnesses

I did not bend or change the sending unit arm from the received position

How can I calibrate the gauge?

I have taken the gauge out of the console and looked for a way to reposition the needle . . .its a sealed unit with all the plastic seams welded . . .no go.

Any ideas would be greatly appreciated.

Thanks

Johnny, did that particular guage work ok before you went into the tank? That seams to be what shows between the lines. Camaro's use a 90 ohm fuel sender. Auto meter makes several different part number gas gauges, for different cars that use different ohm value senders. If it never worked right, it's probably the wrong guage for the car. If it did work and doesn't now, it has to be from something in the tank that was changed.

Most likely will be the sender ground wire. This connects from the "cap" on the sending unit to the body above and in front of the gas tank. If it's not there, not connected on one end or the other, or not getting a good connection (paint?) it could cause excessive resistance and give you that bad reading. If you have an ohm meter, read from the (disconnected) tan wire in the trunk to one of the tailight housings. With a full tank it should read 90 ohms. If it doesn't, check from the tan wire to the tank itself. If that reads 90, your ground is bad. If it doesn't, something is wrong with the sending unit.

Hey Jim,

First off . .great looking 68 vert . .love the stripe

The gauge read wrong from the start. I installed the new gauges the same time as I replaced the sender unit. Not sure if i remember where the tan wire is that you are refering to. Would it come into the trunk area and run the harness down the driver side to the front?

Thanks

Hey Jim,

Just read a post on the same topic from August 8th I see what you are talking about. I will test the tan wire and report back - thanks

it connects in the trunk, under the gas filler. same place as the plate light