This is Fender’s acceptable standard, even their American basses with noiseless pickup have the same problem.
Check under the bridge if they have scratched the chrome off where the ground wire makes contact with the bridge. Another area is the pickup cavity if it’s properly shielded. Not so much on the split p pickup but all of the good ones usually have a ground wire from the pickup and bolt on to the shielded cavity. I like the brass plate under the pickups that Fender uses on the high end models.
You can also put a spring under the knobs between the knobs and the washers to make the metal to metal contact this happened to one of my bass and it was the last thing I did before it went away. I use the paint and I painted the pot holes all the way up no more hum.
I would run a continuity test between all external metal parts to rule out any grounding issues (bridge to pots, pot to pot, pots to jack, jack to bridge). I would also tap each pickup pole with a screwdriver to make sure both split coils are working (they should be hum canceling each other).
If everything checks out, I would also try a new cable, and maybe move rooms to see if that gets rid of the hum.
If the grounding and pickups are ok, perhaps something in the environment has changed that is now causing 60 cycle hum.
Thank you to @Wombat-metal , @Al1885 , @RuknRole , @Barney . I know it’s not the environment because it was happening when I was in San Diego and now it’s happening in NJ. I’ll try all these methods and see what turns up.
OK, so I did a continuity check on the bridge, jack and pots and there is continuity. I took the bridge off and found that the ground wire wasn’t soldered to the bridge. It was just the ground wire with about 3/4" of insulation removed and pressed between the bridge and the body. There wasn’t any place to solder the wire, so I guess the assembly procedure is just that. The ground wire had made an indentation in the body where it was pressed between the two. Before I re-attached the bridge, I re-positioned the bare part of the ground wire to a different location, put back the bridge and put on the strings. It must have helped because no more hum! Not really thrilled with the way the bridge is grounded, but I guess it will do for now.
Thanks to everyone who lent a hand with this problem.
I have stuck the shielding to the body under the bridge (not the whole area, just a strip) and fanned out the wire to maximise contact area-I did solder one to the tape and flattened it also.
Then sand back the underside of the bridge plating.
Added bonus of soldering it is that you don’t accidently pull it thru into the cavity-I know this how?
Another thing you can do with the tape that @Barney mentions, is put it on the body of the bass under the wire, keeps continuity even when the wire makes it’s way into the wood over time.
A lot of good tips. I may just put down tape under the bridge of my Mustang PJ
Which will be my next project bass. Small p.
Brand new bass why change? Well, the bridge pickup has a reputation of being lackluster, and some folks here have seen that. So I now have a set of DiMarzio DP126 Model P/J on the way. To go with that I have a set of Rotosound 77 Monel flats, which I find pair very well with the Model P/J.
And finally, the elimination of that 3-way switch. When I get it I will measure and see if I can do a stacked pot, and if so will do two stacked pots vol/tone vol/tone, if not a more conventional vol vol and tone where the switch was.
I started doing this as habit when I have the strings off on all the basses after some work from the last luthier showed me this trick on the 2-string slide bass.
I like that I can adjust the fit without taking it off the bass, and I like the length. I have short legs and regular straps are often just too short for my torso
Also, sometimes the ground wire is a bit short or gets tugged back into the electronics cavity by accident. Always a good idea to have a little slack in it.
