I'm trying to do this mod:

Noise gate mod: This mod will quieten the Muff while not playing, thus a noise gate. To do this, add a 100k trimpot (wired as a variable resistor) parallel to the 100k to ground of the second gain stage (R14). The trimpot can be adjusted to taste to get the max noise gate effect.

I wanted to make it switchable so I wired it like it is in the diagram. It works when the pot is bypassed but when I select the pot no signal is passed. I also tried a variety of ways of wiring the different lugs and jumpering, etc. and still nothing.

To any of you real modders, what dumb mistake did I make this time?
noise gate.bmp
...to give your love no matter what is what she said...
Remove the red wire. Then you got it.

I played with this mod on my BM for sooo long. I tweaked it so much. Its a terrible terrible mod, does not work at all.

Also where did you find the info for that mod?
Here's where I got the info

While we're at it, I'm going to be doing a switchable mid boost mod:

Mid control mod: This mod is beloved by both guitar players as by bassplayers to regain the mids in the sound, mids that are so needed to be heard in the mix. With the next control you can dial in anything from a (huge) mid cut to a mid boost. Note that by boosting the mids you'll lose the Muff's character; still, it is a very nice addition! Replace C1 with a 22n cap Replace R2 with a 22k to 25k potmeter (wired as a variable resistor) with a 1k resistor wired in series.

Care to figure out my drawing?

As always kurt, thanks for your help. I would have no working pedals without you
mid boost.bmp
...to give your love no matter what is what she said...

Play with Duncans Tone Stack Calculator.....you can see the frequency curve as you change different components. I used it a ton when modding my BM....

I forget now but I am pretty sure I have a 0.0047mF and 0.022mF cap on C1, switchable.

I would also change all those 1mF electro caps in the signal path to 0.1mF film. Makes your sound clearer, smooth and tightens the bass up. It is a mod that is widely accepted.
Cool. When you say the noise gate is a terrible mod is it because when you turn it up enough to reduce any noise, it also reduces saturation and clarity? Or did i screw something else up?
...to give your love no matter what is what she said...
It does absolutely nothing if I remember correctly. I believe it just acts like a really bad volume/gain control.

You can try it but dont drill a hole for a switch.
Yeah I did it just now and it sucks. But I noticed something wierd...on the BM mod site, there's a reference photo and while he clearly says to wire a pot in parallel with R14, he has R21 circled in the pic. I'll try putting it on R21 just for giggles but if it does nothing, I'm done with that mod. Thanks a lot for your help.
...to give your love no matter what is what she said...
I just put it on R21 and I need to play around with it for a bit but it seems to be doing what it's supposed to. I noticed a volume drop in addition to noise reduction but it didn't murder my tone like it did on R14. Or maybe I want it to work so desperately that I'm imagining it. Either way, I'm going to run with it.
...to give your love no matter what is what she said...