Neck pickup loses most volume when tone knob is in closed position

The title describes a lot of it. I've been having this problem for a while, it happened after i installed a 4 way selector. The neck pickup's volume gets reduced to almost nothing when the tone is all the way closed and the bridge pickup is still normal. Also since the modification, much of the lower tones from the pickup have been sucked out which... sucks because it sounded great. Anyone know what's going on? i'd prefer not to have to buy new pickup but i will if it comes to it.

You need to post a picture or a diagram of how it is wired. Don't post the diagram you used, but trace out exactly how it is wired. I bet if you do that, you will be able to solve the problem yourself.

It has worked for me. "Wait! Why is that wire going there when it should be going here?"

The wire from the tone control should run to the lug on the vol. pot that has the line out to the jack, if it is connected to the lug that has the line to the switch it will act the way you describe...