Guitar Wiring Explored: Adding a Blower Switch
We’ve all been there: you’ve dialed in a sweet rhythm tone – the neck volume is on seven and the bridge volume is on… whatever it’s on, you weren’t looking. And the tone controls are turned to the precise value of “where it sounds right.” You’re grooving away and suddenly it’s time for the solo! You switch to the bridge pickup, roll all the controls up to full, and rock out.
At the end of your “moment,” it’s time to get back to that sweet rhythm sound. But where the heck did you have all the controls set? There’s no time to dial it all again again, you’ll just have to make do. There must be a better way.
I’m sure you’ve heard of a “blower switch” before, so you’ve probably seen where I’m going with this. It’s a fairly simple mod that gives you an extra switch on the guitar. When the switch is disengaged, the guitar behaves as normal with all the switches and controls performing in the normal way. But when you flip the switch, all the other switches and controls on the guitar are bypassed, and the bridge pickup is connected straight to the jack. It’s like you’ve flipped to the bridge pickup and turned the volume and tone controls all the way up.
You can use any DPDT on/on switch – this is the type of switch that you find on push/pull pots, and it’s the standard “mini toggle” switch you find on most guitar parts websites too.
In order to make this article relevant to as many types of guitar as possible I’m going to approach the wiring in a slightly abstracted way. Here’s a diagram of how at least part of the wiring in your guitar probably works:
There will be a wire from your bridge pickup to ground, and there will be an output wire too (represented by the blue wire – Wire X – on the diagram). On a single coil Duncan pickup, this output wire will be the white wire; on a humbucker it’s probably the black wire (the red and white wires aren’t relevant to this mod). Point A on the diagram represents wherever that output wire connects to – a switch, a volume control, or whatever.
Similarly, with the jack, there is a hot and a ground connection. The hot connection is represented by the red wire – Wire Y – on the diagram, and the point to which this wire is connected is Point B.
This is a diagram of what the wiring will look like after the mod is completed:
In order to complete the mod, first disconnect Wire X from Point A, and instead connect it to the middle contact of one side of the switch. Then add another wire from the same side to Point A, such that when the switch is turned off, Wire X is still connected through the switch to Point A.
Next, follow a similar process with Wire Y from the jack – disconnect it from Point B, and connected it to the center lug on the other side of the switch. Then add a wire to Point B from the same side, again so that it is connected when the switch is turned off.
Finally, add a short jumper wire across the two as-yet unused contacts on the switch. This will mean that when the switch is turned on, the bridge output is connected directly to the jack, and the rest of the guitar wiring is disconnected completely. And you’re done!
This mod is great for switching between rhythm and lead tones instantly – much like the Jazzmaster circuit (although much less complicated). Do you have any other simple mods that you like to apply to guitars to simplify live playing?