Rooky question about wiring

Smeigel_12000

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Hi all,

I'm currently trying to wire a Starfire III with 50's Gibson schematics. It's one of my first soldering projects. I have all parts, except the neck pickup, so I wired everything and the ends going to the neck pickup are still unconnected.

Now if I try out the circuit on my amp by plugging it in, I hear the bridge pickup is working (tried playing in front of it with an acoustic guitar), but there's crazy hum at all volumes. Is that because the neck pickup is still unconnected or did I do something wrong? If I measure with my multimeter everything seems to be grounded. The volume of the neck pot is completely turned off.
 

Rocky

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First thing I would look at is if you have the bridge/strings grounded. Not sure where the wire is on a SF III, but it's likely a wire that grounds to the Bigsby at the hinge.
 

Smeigel_12000

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Bridge is not grounded yet because the harness is not installed in the guitar. It’s really just wires, pots, switch and input.
 

lungimsam

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Since the harness is outside for now try to post some detailed pics so we can see what’s goin on there.

If you touch the pot shell that connects to the ground lug of the output jack with your finger, does the noise go away? Tap with a screwdriver or other metal object on the pickup while finger on aforementioned pot shell. Can you hear the tapping in the speaker? If the answer is yes to both then all is well so far. Wire on!

If not then we need to see some pics to know if the grounding circuit is wired correct or not and with no ground loops.
 
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Smeigel_12000

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When I touch the pot shell connected to the ground lug of the output the sound gets weaker but far from gone.

when I touch a potshell and tap on the pickup I do hear it in the speaker.

here are some pictures. Forgive me my sloppy soldering and mixed color wires. I used some wires I had lying around.

I used plugs to connect the pickups. This way I can easily experiment with different pickups in the future to see what matches best with my needs. For now it will be two original 60's dearmonds.
 

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GAD

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Common cause of buzzing is wiring the output jack backwards.
 

BradHK

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I could be seeing things but it looks like your output and ground on the selector switch are backwards
 

Smeigel_12000

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The inner lug of the output jack is now wired as ground. The center metal part of the switch is also ground.
 

BradHK

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Is it wired like the top diagram below? From the photo above it looked like the “output” connection in the below diagram which should go to the positive side of the output jack was wired to ground through the back of one of your pots and the “ground” lug was wired to your jack.

1650569612556.jpeg
 

Smeigel_12000

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I wired it like the diagram. The black wire goes to the middle pot position. I understand it looks a bit funky on the picture
 

Smeigel_12000

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oke, apparently some of my solder joints were pretty bad. Some came loose during installation. I now have both working. Still some hum, but with my SG with P90's the hum is pretty much the same. It's inheritance of the Dyna I guess. I think I'll leave it this way for now and wait for my next Dyna coming my way to test it out on a decent tube amp. Thanks for thinking along (y)
 

jp

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Try using a multimeter to test continuity and check your ground connections throughout the harness. Here's a great video to do simple checks.

 
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