So I'm converting my Squier strat to an HSH setup, just because I can really, and was wondering whether it's acceptable just to desolder the wires attached to the current single coils from the pickup and then solder the ground to the mesh of the humbucker and the hot to the humbuckers hot. Is this a plausible way of doing things without ****ing up the rest of the wiring I'm not as confident to delve into? All input is appreciated.
I guess it'd be possible, but you'd be much better off desoldering the single coil wires from the switch and attaching the humbuckers instead. If you think about it, you're doing the same thing, just at the other end of the wire.
Also, I'm not wrong in my belief that the mesh is the ground and the wire is a hot am I? Complete beginner to this.
You're right. Not all pickups have that kind of 2-conductor wire, but of the ones that do, the braid ("mesh", as you call it) is ground and the wire is hot.

But yes, don't go cutting or desoldering the wire at the pickups themselves. That just ruins the pickup you're taking out and makes it more fiddly to install the new one. Desolder or cut the wire at the switch or pots (wherever it's connected) and solder the new pickups to the same place.
Yes, I know everything. No, I can't play worth a damn.
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