Thursday, 29 January 2015

Wiring the 11 Way Switch

Given the choice of tones selected (see previous post) I used my spreadsheet to narrow down the wiring options and create a wiring guide. Rather than attempt to draw spaghetti I use a simple colour coded matrix that tells me which lug on the switch gets connected where. I have picked the wiring options where the bridge pickup is always wired to Jumper "a" and ground. So only the middle and neck pickups are wired to the common lugs of the switch

Fortunately the wafers on my switch are white so I was able to mark the wafer by each lug with the colour code from my spreadsheet so that I didn't have to keep referring back to it.

With the switch colour coded, all I needed to do was connect all the lugs of one colour to each other. Eg all the red lugs connected together.

One of the lessons learned from this was to make sure that the colours of the sharpies I was using to mark the wafers matched the colours of the wires I was using. Also make sure the colour coding on the spreadsheet was the same. It just makes things easier

I didn't have a yellow sharpie so I ended up substituting green for yellow on my diagram.

Like the six way switch I wired to my Gretsch I decided to use solid core jumper wires because it makes for neater wiring. I wanted to use a continuous wire to wire up each of the colours rather then trying to wire point to point. Doing so meant that each lug was only soldered once and the wire could hold itself in place. My first attempt with the green wire was a bit fiddly. I tried to strip a gap in the wire at each point where I would need to solder it. This worked but was very time consuming. I think the result looked quite good.

But then I realised I had no black jumper cables, so this time I came up with a different technique. I used a bare wire and threaded on a piece of heat shrink between the lugs after each weld. This made the process a lot quicker. So I used the same approach with the blue wire and some blue heat shrink.

For the red wire I didn't have any heatshrink so I used the insulation off a thicker red wire to create sleeves.

A lesson learnt from wiring the six way switch on my Gretsch was that it is much easier to solder the wires to the lugs if you pre-tin the wire and the lug. When I was using the bare wire I simply heated the wire and melted some solder along the whole length of it. You don't need a whole lot of solder just a thin coat. The same with the lugs, just add a small amount of solder. If you don't pre-tin, then sometimes the solder will not flow around the wire and lug very well and things will get hot.You also run the risk of getting an intermittent connection.

When wiring the lugs together, you need to try and pick a route that doesn't make it hard for you to wire up the remaining tabs. There are some ways of making things easier.

You don't have to start your wiring run from the first switch position. You can start and end anywhere. So you can avoid the longest cable run or an awkward join by using those lugs for the start and end.

If you are joining lugs on the same wafer you don't have to go around the edge, you can put the wires through the spaces between wafers. But take care not to block the operation of the switch.

If you need to join lugs between the top wafer and the bottom wafer try and do so via a lug on the middle wafer so that the wires run on diagonals. Of course if you have already soldered a lug in between your unsoldered lugs then you can go ahead and fly over the top

The aim is to try and keep everything neat and tidy and use short cable runs where possible. There is not a lot of room inside the cavity for the switch so the more compact the better.