Need some help, 50s wiring with master volume and master tone problem SOLVED

[Roxy13]

Ok, I am baffled so I'm going to post this up and see what you all have to say.

I used this wiring diagram on a LP style guitar with 2 P90s. My tone pot barely makes any difference from 10 to 0 and I don't know why. The pot is good and meters as expected on the sweep. The cap reads 0.022 uF as it should.

 

[BadPenguin]

Ok, I am baffled so I'm going to post this up and see what you all have to say.

I used this wiring diagram on a LP style guitar with 2 P90s. My tone pot barely makes any difference from 10 to 0 and I don't know why. The pot is good and meters as expected on the sweep. The cap reads 0.022 uF as it should.

View attachment 514157

Hey Roxy, ground the center tab on the tone pot. An alligator clip can do for testing. Have fun!

 

[Roxy13]

Hey Roxy, ground the center tab on the tone pot. An alligator clip can do for testing. Have fun!

It is. I think they showed that on that diagram anyway with how they show the lug (the circle) with a line to the pot.

This is the first time I've done 50s wiring with a master volume and tone. I did modern once on an ESP guitar for someone.

 

[BadPenguin]

2 Humbuckers/3-Way Lever Switch/2 Volumes/2 Tones (guitarelectronics.com)

Same as this, just ignore the 3 way in this diagram.

 

[Roxy13]

Let me spell it all out:

Neck pickup is connected to the lug on the switch in the up posiiton. Bridge pickup is connected to the lug on the switch in the down position. Output is connected to the bottom lug of the voume pot (where a pickup lead would normally be). Jack and cap leg are soldered to middle lug of volume pot. From there the cap's other leg is on the bottom lug of the tone pot. And the jack wire goes tto the jack. Pots are grounded together by a bus wire.

 

[Roxy13]

I should also say I've probably made 100 typical LP/SG/335/175 harnesses using 2 vol and 2 tone in both 50s and modern.

 

[E.T.]

Have you tested everything in-situ? If so the only thing I can think is an inadvertent dry joint on the tone pot ground. More than once I've thought there was a solid joint and found a bunch of flux had pooled underneath it. Sometimes an excessively smooth or contaminated pot surface will do that. Often happens if you're using pots made of metal with a slightly yellowish tinge to it (I think it's an anti-corrosion coating of some form, cheaper than making the shell out of proper steel), the solution to which is to "key" the pot under the planned joint with some coarse grit sandpaper so you can be sure the solder is actually binding.

 

[Roxy13]

Yep, I found it now that the guitar is back here. That ground lug on the tone pot had broken loose. I'm not the one who put in the initial wiring. All I did was change it from 2 volumes and 2 tones to 1 volume and 1 tone so I had never touched the tone pot. I think that solder joint may have broken on it's way home with it's owner, which would explain why it was fine here and not after it left. I'm going to chalk that one up to "shit happens" for lack of another reason here.

So what I did was put in a new switch with vintage braided wire and I actually connected to the pickups in the control cavity. That way if the owner wants it changed back again I can do it quickly and have long enough wiring to do so. And then of course I connected the switch output and and lead to the jack to the volume pot. And connected my new jack lead to the jack.

I also did some work in the pickup cavities themselves as they are routed in a rather oddball way. This is a luthier built guitar and my understanding is that it was either the first or one of the first builds by this luthier. And the neck pickup route was cut an angle for some reason. Which made the neck pickup also sit an angle. So I put a wedge in there to keep it straight.

But, we are all solved now. I guess it was one of those days. That ground solder broke, and they said the amp was acting up and there was a third thing they had go wrong too And then I had to get involved since I was the one who did the wiring.

Thanks everyone though for trying to help!