Need advice - rewiring a P-Bass Squier

Discussion in 'Pickups & Electronics [BG]' started by PapaCap, Dec 2, 2007.

  1. PapaCap

    PapaCap Guest

    Dec 2, 2007
    Hey guys. First time user.

    I bought a used P-Bass Squier (I think that's what it is, somebody took off all the stickers) and the volume pot doesn't work right. If you barely turn it, the entire volume shuts off. So I bought a new pot/cap kit off eBay, rewired it and it's doing the same thing. I checked the continuity to the bridge ground and it's good. On the back of the pickguard, the aluminum grounding tape is a little chewed up, but it looks okay (I plan on replacing this next). I'm just wondering if bad pickups can do something like this. I figure they'd either work or don't work. Or wouldn't have anything to do with the pots. Anyone ever experience this? Do I have the pickups rewired backward?

    Any info is appreciated. Thanks guys!

    PapaCap
    :bassist:
     
  2. PapaCap

    PapaCap Guest

    Dec 2, 2007
    I tested the resistance for each pickup and it was a little over 3k ohms each. I attached them in serial and it was around 6.5k ohms. Is that an acceptable level?

    Anyway, I plan on removing the bridge ground and seeing if that helps. Then I'll attach a different ground to the bridge to see if that does anything.

    Anyone have any suggestions I'd be more than happy to hear 'em. Buehler?

    PC
    :confused:
     
  3. Rodent

    Rodent A Killer Pickup Line™ Commercial User

    Dec 20, 2004
    Upper Left Corner (Seattle)
    Player-Builder-Founder: Honey Badger Pickups & Regenerate Guitar Works
    what type of pot taper did you buy - linear or log? if everything is wired correctly, this is the culprit right here

    I'd also be interesting to know what ohm value they sold you ... interesting, but not critical to this discussion

    all the best,

    R
     
  4. PapaCap

    PapaCap Guest

    Dec 2, 2007
    Hey Rodent. Thanks for responding.

    The pots I bought are 250k ohm CTS pots (Fender part # 0019064000) that say 'AUD' on them (I assume that means audio). Those are logarithmic, right? Are those correct?

    Thanks for that Hal. I used those schematics to wire it the first time, then I used the Standard P-Bass to wire it again. The same thing happens. The bass outputs with volume wide open, but if you barely turn the volume pot, the signal drops drastically. Like a 5 degree turn shuts the volume off completely. If you keep turning it, it makes a couple popping noises. And, of course, I cleaned the old pots with contact cleaner (first thing I did). I didn't clean the new ones cause they're, like, new.

    Any other suggestions?

    PC

    BTW-does it matter which way you wire the capacitor? I mean is there a + and - end? Also, does it matter which way you wire the pickups? Unlike other standard P-bass pickups, this one has a white wire and red wire with a blue wire connecting them to serial. Most others have white and black wires. Are these standard wires or is this an aftermarket pickup set?
     
  5. Did you follow a NEW wire diagram when you replaced the pots? Some people screw them all up then can't figure it out and sell the guitar.

    Take your ohm meter and attach it to the pickup output wires. Wiggle, jiggle, and move the wires around. You should never lose continuity. Next ohm out your pot. Open your volume ALL the way open. Should read 0 ohms. Now slowly close the volume down. Ohms should ramp up then ramp up even faster towards the end of the taper. If you get sudden drops or it goes to 1.___ during the turning, unsolder all of your wires and try it again. IF YOU OVERHEAT THE POT IT WILL NOT WORK. If your pot passes these tests, make sure that the "hot" (either center lug or one of the sides) is going to the Hot on your output jack. Plug in a cord and check for 0 ohms from your cords tip to the hot lug on the pot. If you pass that test then ohm from the back of the pot (both pots) to the foil shield then to ground. If all that is good, plug the bass into the amp with the pick guard removed and pluck the strings or tap the pols of the coils with a screwdriver.

    Tone control should only use 2 lugs on the pot. It should have one wire and one wire only running to it. The hot taped directly from your "white" wire from your pickups.

    The volume should only have the hot coming into it and the hot coming out and going DIRECTLY to the output jack.

    Do not hold your solder iron to the lugs of the pot for more than two seconds. That will allow you plenty of time to get the wire soldered and then some.

    Audio taper/ linear taper- means nothing to anyone but you. The human ear does not hear "linearly" it is more like logarithmic. You will simply have to turn a linear taper more to get a change in your volume output. Which only = you having more time with your hands on the volume knob and not playing the guitar. It will still work EITHER way.

    ** de-solder your pickups BEFORE ohming out the circuit. If you do not do that you will always be ohming the pickups ***

    Yes, those are probably after market with a coil tap. Grab the two wires with the highest resistance between them. Designate one color for hot and one for cold. Black is normally cold. If your output is weak and tinney reverse the two wires and try again.
     
  6. kyral210

    kyral210

    Sep 14, 2007
    UK
    I got a squire P-Bass off ebay and then tech'ed it out a little. It made a good second bass for gigs. Below is a video of me using it:

    http://uk.youtube.com/watch?v=LbBGqIF80nQ&feature=related

    Here is what I did to it:

    1 // Take out those crappy squire pickups and put in an EMG Select P-Bass pickup. its not amazing, but frankly anything better would be wasted on a squire.

    2 // Graph Tech P-bass nut. I had to shim this to get it to the right height (1mm shim should do it). You want to have a clearance of 0.3mm on the bass side and 0.2mm on the treble side. to check this, put a capo on the 3rd fret, and use feeler gauges on the 1st fret between the fret wire and the underside of the string.

    3 // Good quality pots and wiring can't be beaten. I don't know what your kit contained, but 90% of wire you get is low quality. I love vintage wire with the pull back braided cover. Maybe it sin my mind, but I think it adds a smooth character to the bass.

    4 // Most importantly of all, give your bass the correct setup! The Fender support page gives you the measurements for your bass setup. Following this will improve the feel of your bass no end! I would also strongly recommend some radius gauges. With these, set the saddle heights to match that of the fret board at the 12th fret. This helps bring out the evenness of tone in any instrument.