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Advice appreciated - American Fender P pickups low output

Discussion in 'Pickups & Electronics [BG]' started by Mr. Business, Apr 19, 2017.


  1. IMG_0137.JPG I just got a set of American Fender P bass pickups and I'm trying to troubleshoot why the output is so low. I'm used to these pickups and have them in a couple basses, but these are only putting out about half volume. The output is even from string to string and pickup heights are correct. Everything looks right. Do y'all notice anything out of place or do you have any suggestions?
     
  2. Killed_by_Death

    Killed_by_Death Snaggletooth

    Jan 2, 2015
    heart of darkness
    What is that extra black wire that's not connected to anything?
    If that is stuffed in the cavity, it could be bleeding the signal out to ground.
     
  3. I'll look into that a little further. It appeared to me that they just left a little of the wire dangling off and I didn't think it was in contact with anything. I suppose that is the logical place to start.
     
  4. wcriley

    wcriley

    Apr 5, 2010
    Western PA
    My guess is that it's the ground wire for the bridge.
     
  5. I thought killed was talking about the short wire coming off the volume pot. Isn't the long wire coming off the input for grounding the bridge.
     
  6. Killed_by_Death

    Killed_by_Death Snaggletooth

    Jan 2, 2015
    heart of darkness
    Yeah, I didn't think about that being the bridge wire. As long as that is connected to the bridge & not just loose in the cavity, looks alright.
     
  7. Ya. I had it grounded. This was a pic from the seller and the bridge ground was just wrapped around funny from shipping.
     
  8. Spidey2112

    Spidey2112

    Aug 3, 2016
    I had low output from the bridge pickup on a Washburn Renegade, when switched to just that pickup... turns out, it was bad... not totally, just a little. I'm assuming a P is a series config, and I seriously doubt that both are bad. Is there a spec'd ohm measurement you can compare to, for each pickup... out of circuit, of course.
     
  9. Killed_by_Death

    Killed_by_Death Snaggletooth

    Jan 2, 2015
    heart of darkness
    Have you compared the DC Resistance to the ones that are working fine?
     
  10. RobbieK

    RobbieK

    Jun 14, 2003
    Yeah, check the coils, but since the string balance is ok, and a P has its coils in series, it would be pretty odd for both to be partially short, and by the same amount!

    If you've already tried the bass with several different guitar leads, I'm guessing the pots are faulty or the pickups have somehow become demagnetised slightly.

    Try the pickup direct to the jack. While the pickup is removed from the vol pot, check both for resistance and taper.

    Also, were trying this with the tone pot wide open? If the cap is short (cooked/faulty), or the incorrect (too large) value, the tone control will act as a volume.

    If it turns out to be the magnets, there's lots of how-to vids on you-tube for remagnetising. It usually involves some rare earth magnets, and a simple jig.
     
    Mr. Business likes this.
  11. 40Hz

    40Hz Supporting Member

    You might want to simplify and redo some of that wiring just to eliminate anything wonky like a cold joint or an unwanted loop. The fewer the wires and solder joints, the less chance of something going sideways on you. This is the "standard" way to wire a split pickup PB:

    pbwiring.

    If that doesn't cure the problem there's a chance you have a bad coil in one of the pickups, or a bad pot. That can all be easily tested with an inexpensive multimeter. I'd just replace the cap with an .047 polyester film one either way. Those cheap ceramic capacitors can crack and are easily damaged by heat and handling.
     
    Last edited: Apr 19, 2017
  12. EmptyCup

    EmptyCup

    Feb 25, 2013
    Nashville Area
    upload_2017-4-19_22-25-9.
    That "short wire coming off the volume pot" is most likely what's left of the "Ground Lug to Body" shown here coming off the tone pot (although on my three American Standards it is coming off the volume pot). That ground lug gets screwed to the shielding paint inside the cavity.

    Below is a photo of one of mine:

    IMG_6672.JPG
     
    Last edited: Apr 19, 2017
    gregmon79, hopwheels and Mr. Business like this.
  13. wcriley

    wcriley

    Apr 5, 2010
    Western PA
    Has anyone noticed the connection where the pickup hot hits the Vol pot?
    The first thing I'd try is reheating/resoldering it.
     
    Mr. Business and 40Hz like this.
  14. 40Hz

    40Hz Supporting Member

    +1. Reflowing the solder joints is aways a good first stab at repair. Easy to do and it doesn't take much time.
     
    Mr. Business likes this.
  15. RobbieK

    RobbieK

    Jun 14, 2003
    Well spotted. Now that I've downloaded and zoomed, I see what you mean. That's not factory soldering. And from the angle of the wire, I wonder if the cold (black) wire from the pickup is about to break where it's soldered to the vol pot casing...
     
    Mr. Business likes this.
  16. I think you nailed it. On closer inspection only 1 wire is left connected. Heating up the iron and I'll report back.
     
  17. Ok. I'm still getting low output after fixing that one joint. This might have something to do with it though, because I'm getting more volume when I roll the tone.
     
  18. Nickweissmusic

    Nickweissmusic Knows all intervals from one Fred, to Juan octave Supporting Member Commercial User

    Jan 26, 2014
    San Diego, CA
    I teach lessons and perform live music in and around San Diego CA. Sometimes I even make money doing it!
    Hope the suggestions above work, if not, First and foremost, you have to eliminate the obvious. Is it the pick up, or is it somewhere further down the line. You can absolutely wire that pickup directly to the output jack, if it behaves normally then, you know it's somewhere else in the chain. If the leads aren't long enough, just solder a little more wire on, but In the future, these alligator clip jumpers are handy things to have around for just these occasions, you can just clip them to the wires and the lugs on the output jack: NTE Multi-Color Insulated Alligator Clip Lead Set
     
    Mr. Business likes this.
  19. Nickweissmusic

    Nickweissmusic Knows all intervals from one Fred, to Juan octave Supporting Member Commercial User

    Jan 26, 2014
    San Diego, CA
    I teach lessons and perform live music in and around San Diego CA. Sometimes I even make money doing it!
    All right, I still suggest you go with "straight pipes" like I mentioned above to rule out any issues with the pickups themselves, but since the tone knob seems to be affecting volume, there is a very good chance that capacitor is fried. Just looking at it, that giant glob of solder right next to the ceramic would indicate it was put on without using a heat sink. Capacitors can be damaged by heat, so it's always good practice to grab the lead with pliers or hemostats while you are soldering it, to dissipate heat before it reaches the ceramic.
     
    Mr. Business and wcriley like this.
  20. Would anyone like to suggest a cap and where to get it? I saw someone above listed a .047 polyester film, but I really know nothing about caps.