Help troubleshooting P/J bass pickups and controls wiring issue

[43 Base]

This is a P/J bass build, which otherwise turned out epic, but has got some troubles making the right sounds.

I could use some pickup/wiring help from the experts.

The "P" pickup is a Tonerider Precision Plus: DCR 10.6 Alnico 5
The "J" is a Fralin Jazz Bass: DCR 9k Alnico 5

I used this wiring harness from these folks: https://1469music.com/products/xn-fender-pj-bass-precision-bass-wiring-harness-70b

The cavity is painted with black shielding paint and all metal is grounded to it.

Here's what's happening:

So... All pots at full, there's sound. Turning down P volume pot, in only a short distance of its travel, the sound shifts suddenly in tone in sort of a phase-y way. It's not a linear process at all.

Again, all pots turned up, and then turning down just the J pot a small amount, results in a sudden increase in volume.

With the P volume off, though, the J volume has a linear feel and seems to produce normal tones.

Inversely, when the J volume is off, the P volume seems to work normally. But then, once you turn the J volume up, it has no effect until the nearly the end of its travel, where the overall volume drops off sharply.

Moving the tone control doesn't seem to do much but there is some subtle tone alteration.

I'm not a pro at wiring but know enough about soldering to be reasonably good at it.  I followed the wiring diagram closely.

Thoughts?

Pickup incompatibility? Flaw in the harness? Some solder wind up somewhere it shouldn't have?

All responses appreciated...

 

 

[curtisa]

Both pickup's ground wires have a connection to your wiring harness ground?

You're using two pickups from different manufacturers; there's no guarantee they're wound with the same phase relationship. Maybe try reversing the phase of one of the pickups by swapping the hot/ground wires of one pickup?

 

[43 Base]

That was the problem, as suspected by Fralin as well.   Works normally now.  Thanks for the suggestion.