Active pickup issue

I have an old Jazz Bass copy made of parts I had left in my boxes when I moved. I thought it would be fun to build and spent the last days into it. But there's a problem with the active pickups I installed. I borrowed the wiring diagram from a Seymour Duncan Bass Lines I have installed on another project and applied it to a Gotoh active set of pickups for which I didn't have any wiring diagram, and now the bass has lower output when plugged all the way in the output jack than half way in. Of course, it sounds better when the active circuitry is on, but the lack of power makes me believe I fouled something when plugging wires. Anybody has an idea ?