First, you need to determine 1) if the volume pot is working properly at all or 2) if you have it wired up wrong. A test with a meter would be invaluable. NO WAY to scope it out otherwise. No short-cuts here!!
You will need a meter, and one for what you need is not very expensive. Think Radio Shack. There should be a variation in the resistance to current flow through the device as you turn the stem of the pot up and down.
Guitar Center would have a pot and other parts you might need, likely.
You need to be really careful with the 5-way switch. I had a similar problem with a telecaster 3-way switch one time. There is a bit of variation in the design of the five-way switches, and the only way to do it right is to carefully figure out how the switch works, what is connected to what in each position.
EVERY diagram I got from any source was WRONG but the switch worked properly when I got the right things hooked up.
ESPECIALLY make sure you do not have a jumper from one side of the switch to the other wired up in the wrong place, and that the ground is not fastened to the wrong end of the switch.
Just keep looking at it and studying it until you figure out the signal path. Take notes, and when you get it fixed document it.
Good luck, and remember it always seems dark before the dawn, mostly 'cause you've been in the dark so long....don't worry, you'll figure it out!!
Doc Snow
www.myspace.com/bigrfishdoc