Sorry for the desperate nature of the title but I've been battling with this switch issue for months now and have finally decided to ask for as much help as I can. My bass has a MM duel coil pickup between 2 jazz single coil pickups. I've wired the MM (bart) with the diagram for neck single/series/bridge single switching (it's the first diagram on the 2nd page of this link: http://www.bartolini.net/instructions/pickups/passive/switching/4cnd_sw1.htm ) and want the jazz pickups to be wired the same: Neck/series/bridge and each pickup set (mm vs single coils) should have it's own output from the switch (they are then run into the sides of a blend pot so Jazz and MM coils can be blended or isolated) Currently the MM pickup functions as it should through the switch while the jazz pickups don't, the single coils work but together they sound quiet thin... it's not a phase problem as I've just tried switching phases with a switch and wiring them so and I know the switch worked it just didn't have any effect on the sound when the first switch was in the middle. I have a hunch that the Jazz pickups arn't outputting in the middle position and I'm getting a very quiet MM series sound bleeding through somewhere. just a hunch of mine. Is it possible to have the Jazz single coils working in the way I desire on an on/odd/on switch like the one used in the Bart diagram (mines a DT/TT) switch so I'd be using one half for MM and one for Jazz p'ups. Please help me TB people!