I have a MIJ Fender Jazz I bought used that came with Bartolini active pickups. The controls are blend, volume, tone. Since I have had it the bass works great when one pup is on but when blending both of them the volume dies as if there was a phase or polarity problem. I have taken the bass apart and checked the wiring based on some diagrams I found here and at Bart's site. Everything seems fine but I am far from an expert (I play mostly upright). The only other info I can give is that I hear a little bit of noise as I start to turn the blend pot out of full left or full right position. I don't know if this means I should replace the blend pot or is this a more common problem due to faulty wiring that I haven't been able to detect. Thanks in advance for the help.