Low Gain Pickup Response

[minions]

I recently added a DiMarzio Area '67 to the middle position of my Strat and changed the wiring to this:

guitarnuts2.proboards.com/index.cgi?board=schem&action=display&thread=3144

Whenever I switch to the middle pickup, the volume is really low and the tone is very thin-sounding. I have a feeling it has to do with the fact that I'm using 500k pots, but it might be something else. Is there any reason why this is happening? How can I fix/modify it?

Thanks.

[JohnH]

How is the sound when only the middle pup is selected? if it is OK then but thin with other pickups, then it sounds like it is out of phase and needs its wires reversed.
John

[minions]

I figured it out, well partly at least. I thought that when the push-pull pots were down, the middle pickup was selected on its own, and when they were up, the middle pickup wasn't selected at all, etc. But it's actually the reverse. So, the thin sound is coming from the bridge and neck pickups. The neck pickup is a Vintage Vibe SP-90 and the bridge pickup is a Seymour Duncan P-Rails. I assume my middle pickup is just a naturally hotter pickup, but I may be wrong.

[JohnH]

If youve just wired up a new scheme, its a good ides to work trough every switch setting, checking that the pups that are indented are working each time - tapping the poles with a screwdriver tip is a good way to tell. And when you play it normally, none of the combos should be thinner than the single coil sounds unless it is supposed to be out of phase.

John