This is a diagram of the wiring in my 1982 Thunder IA bass. The volume and passive tone pots are 500K log, the active tone pot is 500K with a centre detent, the tone capacitor is 0.022 microfarad Mylar. The dual tone and active on/off switches are DPDT mini toggle switches For convenience, white wires are shown as green
The original wiring of this circuit is unnesessarily complex, a simpler version is shown below.
Wire A now runs directly to the body of the active tone pot. Since all the pots and switches are mounted on a metal plate, if any one of the pot or switch bodies is earthed then they all are, there is absolutely no need to solder this wire to the switch bodies as well.
The red and blue wires at point B were soldered to the middle bottom terminal of the active on/off switch in the original wiring diagram, and there was a wire link between the top and bottom left terminals. If these wires are soldered to the top left terminal as shown, the wire link is redundant and can be omitted. (the switch will still function in exactly the same way, but with fewer solder connections to be made)