I'm going to guess by your saying that you've got another jack in there that you've tacomodded it? If so look at your tacomod wires, take the one carrying the left side audio to the jack and cut it with some wire left on both sides. Solder these ends to one set of contacts on a SPDT normally closed momentary switch (the contacts that correspond with each other. Should be obvious, if not then test with a multimeter or check the switch's schematic) and do the same with the wire corresponding to the right side audio. Make sure the ground wire hasn't been damaged or changed in any way. Tadaa, you're done! Note that this fix is simply blocking the signal from getting to the tacomod jack - this stops nothing for the speaker or the original jack.
Okay that makes sense. My 1/4" is only mono tho. Would this make a difference? or allow me to mute the original output as well?
And Pr0n, im thinking of it..how much ya do it for?