Hey all. I have a Squier strat with 3 single-coil pickups, 5 way switch, 2 tone pots, and 1 volume pot.

I've been cleaning the selector switch and re-soldering a couple things, because 3 of the 5 pickup selector options produced no sound whatsoever. I got all pickups working now except when only using the bridge pickup, which now has a LOUD buzz. Using the combination of bridge/middle pickups has no buzz at all though oddly. This isn't the quiet buzz you get from single-coil pickups either, I still have that on the middle and left (neck) positions.

It seems most likely that it's a grounding issue somewhere in relation to that bridge pickup, but I've tested the resistance with a multimeter (between the jack sleeve ground and all 3 pots ground, as well as the pickup ground) and all showed virtually 0 ohms.

I'm completely stumped. If anyone has an ideas on what the heck is going on here, please let me know. Thanks.
I tried switching the wiring on the bridge and middle pickups, reversing which points on the selector switch they go to. I still have a problem with the bridge pickup even though I'm using what was previously the middle pickup.

Can I assume it's a problem with the selector switch itself? I did clean it and the traces look okay on visual inspection, but that doesn't necessarily mean it's ok.