Why are you wiring in the 3 way switch? With one pickup it won't do anything unless you use it for a coiltap or phase. IMO, the simplest way is to wire the hot wire from the pickup to the middle lug on the volume pot then solder the cap between the middle lugs on the volume and tone pots. Solder the ground to the back of the volume pot and you should be in business. If that doesn't work, I suggest you find a local tech.
each pickup hot goes to one side of the switch, the output of the switch goes to the volume pot clockwise lug, and the center lug of the volume pot goes to the jack.
Thanks Walter, I do have it wired now it just sounds so incredibly loud without a tone cap, not used to the extra volume of no tone pot and cap. The volume pot is a 500K so maybe use a 250K instead?