Fuel Gauge

If I overlooked someone else saying this, I apologize. If the IVR was not working, I don't see how gas gauge would work at all. Not only that, but the temp and oil pressure gauges would not work either. The IVR feeds power to all three of those gauges (at least in my 69). I can think of one way to see if it is a grounding problem. I would use a length of wire with an alligator clip on each end. I would clean off a spot on the Fuel Supply Tube next to where the ground strap connects to it then attach the alligator clip on one end of the wire to that spot. Look at the right side of post #6. Then attach the other end to a KNOWN good ground. Do this in a way such that the wire won't come off during a test drive. If you have a decent multi meter, test this new circuit for continuity. That way you will know the temporary wire makes a good ground. Then turn the key to the ON position. If the IVR, gas gauge, sending unit and all wiring (to include the ground) are working, the gas gauge will work. Then take it for a test drive. Hopefully the gauge will work. Try that for a few days. Then take off the temporary wire. If the gauge starts acting up again, I believe you can chalk it up to a bad ground.