Duo-sonic wiring problem

Carcinogen

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Okay, maybe breaking the rules a bit because it’s not tele related but I figured this is where the brain trust is.

I’m following this diagram to do p90’s in series. They have covers so there is a third braided wire for each PU that needs to be grounded, but when I run them to ground the signal drops out entirely. It just goes dead.

Second problem is that the bridge pickup is somehow always on? Like, the switch seems like B/B+N series/Bridge+neck parallel. The switch is brand new, could it be defective or did I botch this somehow?
 

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Carcinogen

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Oh, and this is the switch.
 

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Tuxedo Poly

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The wiring works by short circuiting the opposite pickup when one is selected.

In the middle position there are no internal switch connections.The signal path is as per diagram from the ground on the top switch lug, neck pickup black, neck pickup yellow, switch middle lug, bridge pickup black, bridge pickup white, switch bottom lug out to vol pot.

Selecting bridge links the ground on the top switch lug to the middle lug and bridge black. Also puts a short across the neck pickup.

Selecting neck - ground on top lug wired to neck black, neck yellow on middle lug switched to bottom lug wired to vol pot. Bridge pickup is short circuited. It could be this is the problem. A multimeter would help diagnose whether the switch is working properly.
 

Boreas

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The wiring works by short circuiting the opposite pickup when one is selected.

In the middle position there are no internal switch connections.The signal path is as per diagram from the ground on the top switch lug, neck pickup black, neck pickup yellow, switch middle lug, bridge pickup black, bridge pickup white, switch bottom lug out to vol pot.

Selecting bridge links the ground on the top switch lug to the middle lug and bridge black. Also puts a short across the neck pickup.

Selecting neck - ground on top lug wired to neck black, neck yellow on middle lug switched to bottom lug wired to vol pot. Bridge pickup is short circuited. It could be this is the problem. A multimeter would help diagnose whether the switch is working properly.

My most used tool for wiring is a $5 automotive continuity tester. For a couple bucks more, you can get one that beeps!

I suspect a "center off" switch may not be the best choice. Typically one uses a center BOTH switch where in center position, all contacts are made. Then one or the other contact is broken when you throw the switch.

A 120V switch certainly offers a more sturdy feel though.
 
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Carcinogen

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My most used tool for wiring is a $5 automotive continuity tester. For a couple bucks more, you can get one that beeps!

I suspect a "center off" switch may not be the best choice. Typically one uses a center BOTH switch where in center position, all contacts are made. Then one or the other contact is broken when you throw the switch.

A 120V switch certainly offers a more sturdy feel though.
Apparently it’s what the old Danelectros used? This goes into more detail https://luthierylabs.com/laboratory/electronics-wiring/passive-electronics/series-wiring/
 

Boreas

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Apparently it’s what the old Danelectros used? This goes into more detail https://luthierylabs.com/laboratory/electronics-wiring/passive-electronics/series-wiring/

Well most of that is over my bald head, but it begs the question - which TYPE of "toggle switch" is depicted in the SD wiring diagram you are using above? I don't see any mention of it. I doubt the switch is defective, but anything is possible.

FWIW, my Duo Sonic came with the typical low-voltage toggle switch. Since I have no experience with the On-Off-On switch you are using, I can't comment on how you would wire it for your purposes. Sorry.
 

Carcinogen

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So, I think part of it was I had the hot/ground reversed on the output jack, I replaced those and the buzzing went away. The bridge pickup cover ground works now and that quit making noise when I touch it, but when I ground the neck pickup cover that pickup drops out entirely. It’s also still doing the same ‘bridge neck/parallel’ thing when it should just be the neck pickup on the top setting. I encountered a similar problem on another guitar and what happened there was the hot wire had a break in the sheath and was coming into contact with the braided ground pickup shield wire. I’m out of brain juice right now so I’ll revisit in a few days and see if that is the culprit.
 




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