I know usually this means the third lug is not grounded to the back of the pot, or that it's a cold joint, but it is grounded, so something else is going on. I have swapped out 3 bridge volume pots, and it's the same problem with each pot. I have checked the whole harness with a multimeter, and get null resistance across all solder joints. I have checked that third lug many times, and with each pot, and it is solid and not a cold joint. That it has been the same with different pots makes me think there is something else going on elsewhere in the circuit. When I roll down the bridge volume, it performs normally, getting quieter smoothly, but then the right about 0 the fullness disappears and a thin quiet clean tone is heard through the pickup at 0. It's a nice clear jangly clean tone, but it shouldn't be there. The switch is grounded adequately to the back of the BV pot - 0 resistance across that solder joint. The ground wire is also adequately soldered all around - 0 resistance at all points. Any help appreciated - what else could it be? Thank you.