Help! Only 1 pickup works

[capd13]

Hello all,
I just finished building my first Pitbull Guitar (PRS-1F) that has 2 humbucker pickups, 4 pots, and a 3-way switch. The bridge pickups work, but when I have the switch to the neck pickups or to the "both" pickup setting no sound at all. Also, when I put the switch on the bridge pickups, I hear some noise from my amp, but the other 2 settings, the amp goes quiet. Not sure if that helps. I checked the wiring and it seems ok to me. Not sure what to do. Any help would be appreciated.

- Chris

[Simon Barden]

Hi and welcome.

It sounds like theres a short to ground from the hot signal on the neck pickup. Because both pickup signals are connected together in the mixed position, both signals get grounded so you get silence. Because the amp is seeing ground on both the hot and ground side of the input, you get silence. With the bridge pickup only selected, you get a bit of the background noise picked up by the pickup and the guitar lead.

The problem is where is the short?

First double check that the neck volume pot isn't turned down (I’ve done that).

Then check if anything changes when you turn the pot, just in case it’s wired back to front or something.

Look for any loose strands of wire from the hot pickup lead or the output connection to the switch that could be touching the grounded pot casing. It only takes one small whisker.

Do the same with the selector switch connections.

We know the signal is OK after the switch as we get sound from the bridge pickup.

Also check that the neck tone pot connection hasn’t got anything touching ground anywhere as it’s taken from the hot pickup connection on the volume pot. If the capacitor is on the tone pot rather than running from the volume pot to the tone pot (it can be done both ways), then one leg is at ground potential and has the potential to bend and touch the hot signal.

There is a chance that the 3-way switch is faulty. Those box type switches aren't my favourite, When they work, they're fine, but they can suddenly swap for working to not working without any intermediate crackly stage. And when they stop working you often get signal shorts.

Can you take some pictures of your wiring and post them here? You can either host elsewhere and link, or for the forum to host them (use the 'insert image' icon) then the picture needs to be .jpg or .png and be less than 1500 pixels on its longest side and under 1Mb, so you''ll almost certainly need a resizing app or basic photo editor. The standard Windows photo viewer has a right click resize option (select 'custom' to type in 1500 pixels).

If it's not obvious, you'll need a multimeter to check continuity. Have you got one?

[McCreed]

Simon pretty much covered everything, but I'll just ask if you have shielded the control cavity?

Copper foil or shielding paint can be sources for shorts, say if a pot has rotated and a solder lug has made contact with the shield.

[Trevor Davies]

Long shot (and because it happened to me):

What about checking if the neck pup mounting screws have cut through and shorted out some wires to/from the switch. I would try removing the top mounting screws and checking if that makes a difference.

[McCreed]

Long shot (and because it happened to me):

What about checking if the neck pup mounting screws have cut through and shorted out some wires to/from the switch. I would try removing the top mounting screws and checking if that makes a difference.

Ah yes! Good call Trevor. We just had this conversation recently, didn't we???

[capd13]

Thanks Guys! it was a ground. McCreed nailed it. one of the terminals on the volume pot had made contact with the shielding. I appreciate your help!