RV-6 Fuel gauge trouble

Second-time poster, non-builder, seeks more advice! One fuel gauge on RV6 erratic, often reads zero when full, will usually begin indicating correctly after about 1/4 tank used, and on occasion the needle will go from full to empty and back a time or two before settling down. Troubleshooting tips, anyone? TM

I had the same

I had the same issues with one of the Van's gages. I replaced it and everything has been fine ever since. New gage cost $35 and took 10 minutes to install. I was glad it was not the sender as that would have taken a lot more time to install.

RV6 erratic fuel qty readings

Had this on my first RV6, with float/resistive type fuel qty sensors. Turned out I was losing electrical ground for sensors where plate holding float assy screwed into inbd side of tank at wing root. Backed all the screws out, tightened back up, good to go. Too much pro-seal in threads? Had to do both sides. Your results may vary. You'll need a right angle ratchet screw driver with a short shank to get in there.