So, I tried to upload a picture but it is too big of a file, I will try and explain it. I have bought a cheap Ibanez as a project shell, my first project. I was just drawing an easy to go by diagram of the wiring. It is HSH, the single coil pickup seems to be bodged. There is a black wire and a white wire coming from the pup itself, also cable soldered to the bottom of the volume pot, those 3 wires seem to meet and have been soldered together at the tip and soldered onto the SIDE of the 5 way pup selector. I was wondering if anyone could shed any light on this because even as a novice at this stuff I know that isn't right.
www.guitarelectronics.com has free wiring diagrams that will help you out
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I gather so much knowledge here and waiting for your new post.thanks for your great post.
if two wires come out of the single coil it's an either or situation. I'll explain why. Preferably the black wire is going to ground and white to hot lead.

here's some additional information
*everything on the back of the potentiometers is ground - even if its not soldered to the same blob of solder.

*in single coils you have one pole. With a single coil the polarity of the current can go either way. Say clockwise or counterclockwise. By itself there is no sound difference. In basic single coils they have two wires and buzz in isolated positions. If you upgrade the pickup to a 4 wire single coil you get more volume as it's a hotter pickup and it doesn't buzz at all from 60 cycle hum.

*in humbuckers you have two poles (north and south) both of which have ins and outs. Ins = signal in (hot lead) , outs = signal out (ground). This is why humbuckers can accentuate on coils to get "coilsplits" and all as you can have half a humbucker working.

but yeah guitarelectronics.com or seymour duncan wiring schematics are fantastic. I recommend seymour duncan because every wire is mentioned.
Thanks for the posts guys! Very helpful. So I don't know if I am understanding this properly, but it sounds like, now you have told me this Tallwood13, cable coming from the potentiometer is an extension of the black wire from my single coil, and its grounding it, so the red wire under all this solder, is probably attached where it should be on the Pickup selector?