What's going on with this wiring?

[Gumkick]

I bought a new guitar from eBay last week, a Hamer Special,

obligatory glamour shot first off.

 

 

The seller said that it had the Duncan stacked P90s in it, I was planning to replace them anyway so I wasn't too concerned when I found that they hummed just as bad as any of my other P90s. However in researching new pickups I did see some references to the stacks and they are supposed to be quiet so I opened it up and found this.

 

 

So if you can see the neck pickup there in the upper left, only the black wire is connected, under that red tape is this,

 

 

the red wire is soldered to the white wire and the green wire to the bare wire, and then they're just taped to the side of the cavity. I'm not even sure why it makes noise. The green wire on the volume pot is the bridge ground wire but as far as I can tell the neck pickup isn't actually grounded at all.

 

 

Finally the bridge pickup has the black wire protruding from the middle, the red and white wires are soldered together and floating (I guess they were under that other bit of tape) and the green and bare wires are connected to the tone pot.

 

I don't know what to make of it. I guess this is one way to wire them as single-coils, they do seem to work but they're noisy and don't sound great. I'm going to look up a regular Hamer humbucker wiring diagram and hook them up correctly and at least check out what they're supposed to sound like.

 

So does this make sense to you guys?

[Prages]

My guess is that the red and white wires are the beginning and ending leads of the stacked coils. They should be soldered to each other and taped off.

The green would be the ground, which can be tied into the shield (the bare wire).

That would leave you with a black wire, and the green/bare wire. Black would be hot, green/bare ground.

I would think you'd want to ground the green/bare wire instead of just taping it off.

That's just a guess. I can't really tell too much about what's going on the pics.

[A_Gitarman]

Sounds like typical SD humbucker wiring to me: red and white are soldered together and taped off, green and bare wires go to ground, and the black wire goes to the volume control/ switch.

If its humming, though, there's probably a loose ground wire somewhere or something.

[edit] on reading your post again, it seems that the neck pickup is wired with one coil grounded (split). That's probably why it's humming. Re-wire the whole thing using the link I provided above and it should take care of everything.

Seriously, if that were mine and I opened it up to see that mess , I'd tear all the wiring out and start over anyways.

[Gumkick]

Thanks for the link, it seems like the bridge is hooked up correctly so I'm not sure why it's noisy. But yeah, I think I'll start from scratch and hope that helps.

[Prages]

Have you double checked the ground wire running from the pots to the bridge? If that wire isn't connected or has a bad solder joint, then the whole guitar is going to be super noisey.

[PunkKitty]

Seriously, if that were mine and I opened it up to see that mess , I'd tear all the wiring out and start over anyways.

I'd do the same thing. I'd reuse the switch, the pots if they were CTS or Bourns and maybe the cap. But the wiring is a mess. I'd rather start over from scratch. I'd also shield the control cavity in the process and eliminate the ground wire between the pots. Let the shield handle the ground.

[Prages]

I'd do the same thing. I'd reuse the switch, the pots if they were CTS or Bourns and maybe the cap. But the wiring is a mess. I'd rather start over from scratch. I'd also shield the control cavity in the process and eliminate the ground wire between the pots. Let the shield handle the ground.

 

 

I could be wrong, but it looks like the cavity is painted with shielding paint. No real need to shield it any further if that's the case.

[Gumkick]

Have you double checked the ground wire running from the pots to the bridge? If that wire isn't connected or has a bad solder joint, then the whole guitar is going to be super noisey.

 

 

Hmm, that's an interesting thought. Those are the green wires connecting all the pots and they seem to be original solder joints (as opposed to the skimpy, dull joints on all the newer, thinner hookup wire). What would I do, disconnect it from the pot and check continuity to the bridge?

 

Anyway I found the SD diagram for 2 vol, 1 tone and everything looks good except that the neck pickup isn't soldered so I'm going to assume it's the soldering and not the wiring that's the problem. But I'll check out that bridge ground wire while I'm in there. The pots are the original Hamer ones, it's a US model so I assume they're adequate.

 

I'm going to replace these pickups anyway but I want to make sure they work in case I decide to sell them. Again thanks for all the help.

[Prages]

You should be able to just take a multimeter set to check continuity and touch the bridge with one probe and the back of a pot with the other. If the wire is connected, the multimeter should tell you.

[megawzrd]

+1 to starting over...that wiring job looks craptacular.

 

Anyways HNGD...I saw that listing and was drooling but the neck repair made me pass. Still a beauty.

[Gumkick]

+1 to starting over...that wiring job looks craptacular. Anyways HNGD...I saw that listing and was drooling but the neck repair made me pass. Still a beauty.

 

 

It was probably stupid of me to bid on it without getting a chance to really examine the repair, risky anyway, but I happened to be looking at it when there were 53 seconds left and I have terrible impulse control when it comes to "bargains". It looks OK, if it holds up then I got a decent deal, if not a great one resale-wise.

 

But this was on my short list of guitars that I was absolutely going to own eventually, I think it'll settle my P90 gas for a good long while.

[EADGBE]

It sounds like a bad wiring job. OK the best thing to do is to make sure the pickup's red and white wires are soldered together and the joins are taped with electrical tape. The black then becomes the pickup's hot. The green then becomes the pickup's ground. Make sure the pickups are grounded. For the other wires make sure the bridge is grounded to one of the pot's back. Make sure all pots are grounded. Make sure the connections aren't touching each other if they shouldn't be.

[PunkKitty]

I could be wrong, but it looks like the cavity is painted with shielding paint. No real need to shield it any further if that's the case.

To me it looks like the cavity is painted with flat black paint. If that is shielding paint, there is a possible ground loop with the ground wire on the back of the pots. There should be only one path to ground.

[_pete_]

Is the switch grounded?

 

 

 

If it were mine, I would rip everything out and do it right.

Nice looking guitar BTW.

[NHLfan2010]

Looks like a fun electrical project! HNGD!

[docjeffrey]

What a mess. I'd just pull everything apart and start over. By the way, is that yellow thing a resistor?

[Gumkick]

What a mess. I'd just pull everything apart and start over. By the way, is that yellow thing a resistor?

 

 

It should be a capacitor, I was going to replace that too, just on general principle. I doubt it's a resistor but that would really be the icing on the cake.