Help! Humbucker only working on one coil!

el_duberino

New member
I've got a Pearly Gates in the neck of my SG Standard. It's been there for years. Recently I swapped out the bridge pickup with a new custom job from JS Moore, and I decided to take the opportunity while the pickguard was off to add a chrome cover over my ostentatious red Pearly Gates. Also, this pickup had a short lead so it was installed backwards (this is the two-conductor type with the grounded sheath and hot core). I took a couple of spare wires and used them to extend the lead so that I could flip the pickup around, which I think is purely aesthetic. Anyway, after this the sound from the neck pickup was just weak and tinny. Everything else was fine, the bridge pickup sounded great, but the PGn was anemic.

I lived with it for a while, but last night I decided to try fixing it by reversing my previous work. I opened it up again, removed the extension wires on the lead, flipped it back around, took off the cover to add some extra tape around the bobbins and over the slugs, then reinstalled the cover (with solder) and put her back in. Still weak and thin. After reading up online, I got out the multimeter and, lo and behold, it only read about 3.5-4k ohms. So I'm thinking that I'm only getting output from one coil. I swear everything looks fine, and I don't see how I could have damaged the wire (it is still protected by the factory tape).

What can I do? Is the pickup ruined? I really like this one in the SG, so if it's shot then I might replace it with the same. I see that the newer PGn comes with 4-conductor wiring, so I could do the coil split if I wanted, but I definitely miss the sweet humbucking sound. Or maybe I should try a Gibson '57 Classic. The PGn came as a matched set with a JB, both with bright red bobbins. They look ridiculous, but the price was right!
 
Re: Help! Humbucker only working on one coil!

Welcome to the forum.

If you had broken either coil, the output would be zero. Hence, you have probably connected something up wrongly.

The braid should still be connected to the baseplate - as should one end of the stud coil.

Two coil ends should be soldered together and insulated. (This joint should not have been disturbed during your original modification.)

The fourth coil end is the output. This is the one that you would originally have disconnected temporarily whilst adding the extension wires.

Either you connected your extension wires to the wrong coil end(s) or you have shorted the coil link joint to ground.
 
Re: Help! Humbucker only working on one coil!

Hmm, thanks for the thoughts. The wiring scheme has the braid soldered to the back of the volume pot and the output wire soldered to the appropriate leg of the pot. When I added the extension wire, I only worked at the end of the lead, not back at the pickup. Since I was measuring directly on the pickup lead with my multimeter, I don't think bad solder joints could be to blame. And I didn't do any modification to the pickup itself other than sliding the cover on and soldering it to the back plate.

I guess I could remove the cover again and retest the resistance.
 
Re: Help! Humbucker only working on one coil!

It doesn't see very likely, but maybe the cover is pressing something against something else and shorting out a coil. If it is in fact a shorted out coil, you should also be able to tell by tapping on the two coils while the guitar is plugged in and checking to see if one is significantly louder than the other. Make sure you disconnect the pickup from the guitar before measuring resistance so that a short elsewhere in the wiring won't influence the reading.
 
Re: Help! Humbucker only working on one coil!

Maybe the wire joining the two coils is grounding against the plate?
 
Re: Help! Humbucker only working on one coil!

I'd bet dollars to donuts that you shorted the coil link on the cover. Take the cover off and it will probably test good.
 
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