Im building a guitar kits usa res o glas model ( i highly recomend them by the way check em out) i planned on uising a rio grande p90 and wiring it to a esquire harness i did by both but i just found out that p90s have 1 wire coming out( really new to p90s) but i have to solder the white wire to the slelector switch and wire the black wire to a pot but i only have the white wire does any body know a way around this or should i just get another kind of pickup.

I did some reading about base plates

Is this what i have to do
http://www.fralinpickups.com/bplate.asp but with a p90. but theres alot of wax on bottom wich i think is twisting these to wires together( i have the white wire which goes to the swticher) but theres also a silver metal wire coming from the bottom as well it apears to be solderd to somthing as well then it goes through the wax and it comes out with the white wire in the middle with the metal wire covering it and plastic covers the metal. At the end of the wire were the plastic ends shows the white wire again and the metal is just twisted to the side. Should i do the baseplate thing but there's the wax or do think i could solder the metal wire to the pot. But i would like to get some other opinons
I'm having issues understanding this myself. I bought a Tonerider Rebel P-90 (humbucker sized P-90) and was planning on wiring it into my semi-hollow myself, replacing the neck humbucker.

The Tonerider diagrams say, verbatim: "Standard R90 installation involves pulling back the braided shield (wire snips can help) and soldering it to the back of the correct voiume pot. The central “hot” wire is soldered to the left lug of the pot." This confuses me. Does the shielding wire act as the ground? Do I need to solder it to something? I'd much rather simply pull the pickups out and switch wires- the old stock pickups are junk anyway. Is that doable, going from a humbucker to a P-90?

I was really hoping I wasn't going to have to fish all the pieces out, but it sounds like the wiring's different enough that that may not be an option.
Shielding is ground. It goes to the back of the volume pot.
"Let me tell you something about Rebels, Obi-Wayne. They want you to come get them, they LOVE it."
Okay i get it i solder the braided wire to the volume pot and the white wire to the switch okay. i will prob report back if this works for me or not thanks
Another question on this. I'm wiring mine into a semi-hollow, and I'm not sure I want to try and fish the volume pot out to solder to it. Would it be doable to solder the ground wire from the old pickup to the braided wire, or is this a bad idea?
All right i wired everything and got some problems 1st postion and 3rd postion dont make a sound middle postion makes sound but its very quiet and "flat". If anyone has any suggestions that would be great.
1 and 3 arent working? i didnt see a wiring setup for you, is it 2 p90s? switching= neck/bridge, neck, bridge?
if so, then i would agree something with the bridge isnt right. it wouldnt be your wires reversed, because that would still make sound, and it sounds like it would be tough to do with what you said before.
check your wires and make sure theyre connected well. pics would also be helpful for us
Sorry for the slow response im actually using just 1 p90 and i wired the sheilding to the back of the volume pot and connected the white wire to the switch (i have a switch because im using esquire wiring) im getting little to no sound in the middle postion and no sound in postion 1and 3 any ideas?