nordstrand nj4se pickup hum

[bucko]

Hi there folks, anyone have any ideas on this. A while ago Ibought Nordstrand nj4se pickups.I had the bridge one put in my jazz 24,worked fine. The neck one put in my 62 reissue. All was fine until recently I wanted the two Nordys put in my 62 jazz. So had this done and now getting hum, even with pickups at same vol, hum only goes when I touch the strings or roll back the tone knob.This bass was quiet before with its stock pickups,Ive had it looked at by a guy who knows his stuff,he says its just jazz pickup hum although he shielded the bass and made it a bit quieter,but I am still getting some hum. Now these Nordys dont come cheap,although great tone but there supposed to be humcancelling. Now onto my Jazz 24,Ihad the original bridge pickup put back in and guess what,noise so bad I couldnt use it. So I ended up putting the 62 stock Jazz pickups into it. Now I get humming if Istand close to my amp or if I solo either pickup ,it only goes quiet when I have pickup select knob in the middle. I would be very grateful if anyone has any advice or input about this.These two great basses used to be quiet ,bad enough one humming but both is so frustrating. Many thanks. Sean