Problem with Duncan quarter pounders (PJ)

I picked up a bass that came with Duncan quarter pounders. I pulled em and put em in something else. Here's the problem.
The bass was fine with the pickups before I put the Duncan's in so I know there is no issues with the electronics.

Ok, so, with just the J on, it's fine. With just the P on it's fine. If I have both on full, there is something strange with the J. The E and A strings sound fine BUT the D and G, and only those, sound super thin, as though I turned all the bass off. Again, ONLY with both pickups on.

I wired white to the center lug and black to the pot case, like all of my basses. I did try flipping these 2 wires .the problem is gone but it now has this wierd sound, much thinner, ALMOST like there is a hint of...wah! ***????

I've changed pups, rewired basses many, many times, never came across this issue.

My thought was maybe the pick-up is bad, but then it should always be bad right? Totally stumped on this .

 

I don't have a meter. I was thinking about wiring both to the jack. I'm now thinking it's something else as i reinstalled the pickup that was in it, same issue. Overheated pot? Sooo strange.

 

Just wired pickups directly to the jack, no change. I'm baffled

 

I got a meter, what and where am I measuring?

 

I get what you're saying but how can it only affect the DG strings??

 

Ok, how can only half of it be out of phase when it's the two coils wired directly together?