Volume pot problem

[ihavenothingprofoundtosay]

Long story short:

neck pickup: SD Phatcat (braided shield wire)
bridge pickup: Carvin S22b (standard 4 wire HB wiring)

Used this wiring diagram.

Got everything wired up (correctly, so far as I can tell), and it's sounding fantastic. . . except when I roll the volume control all the way back, it doesn't turn off!  3 way switch, both pickups, tone control - all good. And the volume pot works normally all throughout the rest of the range of the knob, it just doesn't turn all the way off.

My soldering isn't super great, so that may be an issue (there's a few cold soldered spots, they're definitely connected, though), but I've taken my time & checked as best as I could, so I'm not sure what exactly could be the problem.  I'm not enthusiastic about re-soldering/wiring the whole thing, but if that's what needs to be done...

Suggestions?

 

[Funky Phil]

You need to ground the negative lug on the pot...
                                                                                                                                       
Looking at the pot from the back (and assuming right handed wiring...) with the lugs facing up;   
left to earth (and back of the pot)
middle to output jack hot
right from pickup or selector switch

 

[Super Turbo Deluxe Custom]

Link no worky.

 

[Cagey]

Link no worky.

He's trying to send you here.

 

[Cagey]

I strongly suspect Funky Phil is right. Without that ground, your volume knob is behaving like a variable resistor in series with the signal instead of a potentiometer. Splitting hairs, but there's a difference. With the one, you're just progressively adding resistance to the signal flow. At max R, you won't get much signal through, but there will still be some. With the other you're dropping the signal across the pot's entire impedance and tapping off at various points using the pot's wiper arm. When the arm is all the way to the grounded side, nothing will be coming out.

 

[ihavenothingprofoundtosay]

Success!  Thank you Funky Phil & Cagey - you were correct.

I'd soldered that bit, but not very well - a bit of heating up the solder & pressing a little harder, then soldering again - it's all good!

Also, my sincere apologies for the mal-linkage.  HTML fail!

 

[Cagey]

I'm glad that worked out for you!

Soldering to the back of the pot(s) isn't a great idea and can be a real problem. The OEMs can get away with it because of compartmentalization of procedures and a willingness to do fast half-assed work in the service of saving 2 cents. There's a whole thread on an alternative way of handling that here, if you think you'll be doing any more wiring in the future.