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Another P/J wiring diagram issue

madjazzbass

madjazzbass

Jan 5, 2014
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#1
I've wired up my PJ Bass exactly like this diagram, and it still doesn't work right; I know it's wired correctly cause I've checked it numerous times; the problem is, both pickups won't work when they're both turned up full, I have to back off a little on either pickup in order for the other one to work correctly, but I can't use both pickups all the way turned up What's going on? I need help, Thanks.
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#5
If you test a Jazz pickup with a multimeter and get no ohms - just continuity, is the pickup dead? This is a 4 conductor pickup (Peavey Bass) and I am using the red & black wires. Is it worthwhile to try the green and white wires instead?
 
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#6
You have a Peavey Jazz pickup with 4 wires?

Peavey's humbuckers use red and green for the north coil, and white and black for the south coil. You should show a good resistance reading across red and green, and also across white and black. Any other combo of wires should show an open connection. A typical series wiring would be to connect white and green, use black as ground, and use red as hot. But I've never seen a Peavey Jazz pickup with 4 wires, so I don't know if it follows the same convention as their other humbuckers.

At any rate, if you have the pickup in hand, and you have a multimeter, just test every possible pair of wires among the 4 and look for good resistance ratings across two pairs of wires. Then, you know that each of those pairs are one coil. A "good" reading would typically be between maybe 4k and 12k for a bass pickup.
 
#7
Thanks for the reply. I didn't know to test across red & green, or white & black. But what you said is how both pickups (there is a Precision also with four wires also and it is working) are connected to the pots; red hot, black ground, green & white connected together. But if it isn't a pickup problem I don't know what is wrong because everything looks to be wired correctly.
 
#8
What are the symptoms? Is the pickup making no sound at all? Are you taking these resistance readings with the pickup in the bass and wired to the controls, or have you removed the pickup?

With the green and white connected to each other, you should get resistance across red and black. If you're getting zero ohms, you have a short somewhere. It may be easy to fix, most zero-ohm shorts are either outside the pickup (a stray wire is touching shielding, or something like that) or right on the "surface" of the pickup (the hot wire is frayed and touching shielding). A zero ohm or very low ohm short is almost never anywhere deep inside the pickup or hard to get to. If there is a short deep inside one of the coils, you would still get a resistance reading, it would just be really low (like, 1k ohms instead of 8k or whatever).
 
#9
I am getting no sound at all from the pickup, and I am reading continuity between red and black. I am measuring right on the pickup (although it was still connected to the pot and might have been wide open). If I put one lead on the metal tape over the coils and touch either the red or black solder point(s) on the corners of the pickup I still get full continuity - no resistance. I could be doing something wrong, pickups are not my specialty.
 
#12
I just read this about Jazz pickups... does this change anything I need to do?

"Here’s where we find a significant difference compared to guitar single-coils. The two pickups are wired in reverse to each other so that, like a humbucker, noise-cancellation occurs."
 
#13
motterpaul said:
OK - I will do it later today, and also measure across the other wires for resistance as suggested above. Thanks for your suggestions. BTW: is the Jazz pickup a humbucker?
Click to expand...

Yes, it has two coils inside it and the typical wiring would put them in series mode. The coils are (presumably) reverse wound and reverse polarity so they'd be humbucking.

motterpaul said:
I just read this about Jazz pickups... does this change anything I need to do?

"Here’s where we find a significant difference compared to guitar single-coils. The two pickups are wired in reverse to each other so that, like a humbucker, noise-cancellation occurs."
Click to expand...

No, it doesn't change anything - it doesn't even really apply to your situation. The pickup isn't a single coil. The comment you're quoting really only applies to a pair of true single coil pickups, which are typically built with opposite magnetic polarity and opposite wire direction, such that when used together they are humbucking. But that "reverse" typically happens within the pickup itself, and you don't need to do anything different when wiring the bass. At any rate, if your pickups were out of phase, you'd still get sound, but when operating both pickups together the sound would suddenly get very thin sounding. Either pickup solo'd would sound normal.

Further, the pickup would test "correctly" in terms of the DC resistance reading, regardless of if it's a humbucker or single coil, and regardless of if it's wound backwards or not. If the pickup doesn't give you a good DC resistance reading, we need to figure that out, and no get concerned about control wiring or single coil vs humbucker, etc. etc.
 
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#14
Okay disconnected from controls and disconnecting green & white

Red + Green = 6K ohms
Red + white = 10M (shifts between 8M and 14M)
all other wire combos I get dead short

Note, the other pickup is about 14k
 
#15
6k isn't bad on the red-green coil but it seems like something serious is wrong here.

I hope this isn't insulting, but are you sure you're using the multimeter correctly when you get "dead short" for the other readings? There should be an open circuit between: red and white, green and white, red and black, green and black. 6k sounds right between red and green. There should be about the same reading between black and white.

Any time there's a zero ohm reading, there's a short somewhere. It could be possible that the short is also causing that high reading between red and white, which should be an open circuit. Does the pickup come out of the case or is it potted into the case? Can you show us some photos?
 
#17
You are right, it is an open short between the other wires, no connection. I figured the 6K could be one coil and maybe the other coil died. The pickups are out of the socket and are not potted, they just have some foil tape to hold the copper down on the coil.
 
#18
Yes, it sounds like the coil showing 6k is probably OK and the other one is broken. If it's showing an open circuit there's a broken wire. If it's showing zero ohms there's a short. The coil wire itself is very thin, like a hair. The connection between the coil wire and the lead wires is a common spot for breaks or shorts. On a fender-style pickup that connection is made on an eyelet. In some other brands, it's made simply by soldering the wires together and wrapping the first inches of the lead wire around the coil to keep it secure.

If you show us some photos of the pickup we may be able to point out the problem.
 

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