1967 Fuel Gauge Issue

[Ralph E.]

Did the Toys 4 Tots Cruise this past weekend and now my fuel gauge is stuck at 3/4 full.
How do I check the if the issue is the fuel gauge or sending unit?

[Michael H.]

Re: 1967 Fuel Gauge Issue

Did the Toys 4 Tots Cruise this past weekend and now my fuel gauge is stuck at 3/4 full.
How do I check the if the issue is the fuel gauge or sending unit?

Run a can of Seafoam or Techron thru your tank and see if that helps getting it working again.

Mike

[John D.]

[Ralph E.]

Re: 1967 Fuel Gauge Issue

Thanks John, that is exactly what I needed.
Not sure how I'm going to do the diagnostics all by myself. Appears a helper is needed.

[Richard M.]

Re: 1967 Fuel Gauge Issue

Ralph,

By design, when power is removed from the meter movement(gauge), the last reading remains. Check for power at the rear of the gauge, and also for power at the Pink wire going to the sender. This feed from the IGN source is fused, so if the fuse is blown, this may be your fault.

Rich

[Ralph E.]

Re: 1967 Fuel Gauge Issue

Ralph,

By design, when power is removed from the meter movement(gauge), the last reading remains. Check for power at the rear of the gauge, and also for power at the Pink wire going to the sender. This feed from the IGN source is fused, so if the fuse is blown, this may be your fault.

Rich

Thanks, Not sure which fuse it could be? Have not checked for power yet?

[Edward J.]

Re: 1967 Fuel Gauge Issue

Ralph, a quick look in the fuel tank and make sure the float is not stuck, or sunk. you can also take a coat hanger and bend to hook the arm on sender and move float lever up and down to see if this creates some movement.

[Ralph E.]

Re: 1967 Fuel Gauge Issue

Ralph, a quick look in the fuel tank and make sure the float is not stuck, or sunk. you can also take a coat hanger and bend to hook the arm on sender and move float lever up and down to see if this creates some movement.

Thanks Ed, I tried the coat hanger and lifted and lowered the float with out any change to the gauge.
I removed the spare tire tub for access to the sender and removed all the wired connectors from the sender terminals. Checked the ohms between the pink terminal and ground and got ZERO, expected 100 ohms. Checked the ohms between the pink terminal and the tan terminal on the sender got about 60 ohms, but I cannot move the float at the same time I'm trying to read the ohmmeter. Need a helper. Was about to check the voltage at the pink wire connector with ignition on but got late and I'm cold.
This is as far as I can go without a helper to move the float.

[Richard M.]

Re: 1967 Fuel Gauge Issue

Ralph, Gone all day just checking in. Ironically I was checking a electrical system on a '67 today after body drop yesterday.

The Top fuse marked "B/U LPS GAUGES" supplies power to the Fuel & Temp gauges, Fuel Sender, Park Brake Dash lamp, and BU lamps via the Pink wire. Do your Backup Lamps and Park Brake Dash lamp work? If they do the fuse is good but could be faulty later upstream for fuel gauge circuit.

With IGN on, check both sides of the fuse for 12V. The left side is the source, right side is the output to the circuits above. Pics of fuse panel in this recent Post. If good you should have 12v on the Fuel & Temp gauges Pink wires and Sender Pink wire.

The fuel sender wires pass through the rectangular Body Connector under the dash near the drivers side kick panel. It's a 12 place connector with only 10 positions used. Blk is ground, Pink is +12v, Tan is Sender terminal. Check the GND plug terminal at the sender as those rust easily.

Rich