So here’s where it gets fun.  This whole time, I’ve been calling this project the 7-String LED Guitar (LD-1), so now it’s time to step up. After all, if the LED lighting looks shitty, then I would just be left with a 7 string guitar, with two extra, shiny buttons.  Sitting down to wire this thing, I realized that I probably should have diagrammed this whole damn thing.  Rather than make my life easy, I decided to figure it all out as I went.  Ultimately, this is just a little more difficult than installing strap mounts to a guitar body (sarcasm)…

Step 1 – Test the lights and batteries!  No, really, test everything before you start cutting things apart.  You want to make sure things worked, in the first place.  This helps so when you have a completely new hacked and soldered wiring harness that doesn’t work, you know it’s your own damn fault, and not the materials.  Here’s proof of life (above), with the blue LED strand, plugged straight into the battery pack.

Next, I cut the wire connecting the battery pack, and the LED light strand. The reason I did this, is because we’ll have to install a whole bunch of stuff in between the two, to make everything work according to the design.
 
I picked up a soldering buddy from Adafruit.com.  This REALLY helps to hold things where you want them, while soldering.  In this case, I soldered two modular plugs into the positive and negative wires coming from both the battery pack, as well as the light strand.

After soldering the connections, I used heat shrink tubing to insulate and reinforce the solder joints.  Heat shrink tubing is some handy stuff, that starts out as a large diameter rubber tube.  You cut it to length, slide it over whatever you want to insulate, and use either a hot air gun, or a soldering iron to apply heat.  After a few seconds, the tubing shrinks in place leaving a tight fit.  This is a lot cleaner and more convenient than electrical tape.
I repeated this step with the battery pack.  You can see the plug and play modular ends, and hopefully understand the convenience they bring to the project.

Here’s a shot of the modular wires I connected to the positive and negative lines of the LED light strand.  The reason I used the modular wires, is to I can swap components out of the guitar easily and quickly.  The beats the hell out of permanently soldering things into the guitar body.  If something breaks, or needs replacement, just pop it out, and put the new one in.  Now you might be wondering why I attached an extra set of leads to the LED strand?  Well I plan to run the power in series, from the battery pack, through the on/off switch, into the LED light rings of each button.  There are many more (and probably cleaner) ways that this can be accomplished, but it’s what I decided on.

Proof of life #2 – Once I connected all of my modular jacks, I ran another test to ensure everything worked properly.  This is a whole lot better than testing everything, for the first time, at the very end of the project.  If something doesn’t work now, you have a lot fewer variables to debug. 

Using the pre-drilled pickup wire holes, I fed the business end of the light strand into the lower pickup rout.   

Pulling the LED light strand into the pickup rout,  I wrapped the cavity once, and then passed the light strand through into the neck pickup cavity (using the access hole I drilled back at the beginning of this project).

 Proof of life #3 – I wanted to make sure that not only every thing worked after routing and wrapping the wires, but that it looked cool as well!  Side note – I’ve heard this project described as everything from cool, to gaudy, to “why the hell would anyone add LED lighting to a guitar”.  Let’s just say that if you don’t understand what makes this awesome immediately, then just ignore it.  It’s probably not for you.  In fact, here’s a link to a guitar that might be more your speed.
This is the button that will be used as a killswitch.  This is a momentary “normally on / push off” button, with a red LED light ring.  Two things need to happen to this button: First, I need to add wires that will provide power to the LED light ring.  Second, The guitar’s output jack wire will need to be passed through this button, to enable control of the “signal cut” effect.  Here, you can see the two power wires in place.

This is the lighting control button.  This button needs to control ALL lights on this guitar, including its own LED light ring.  This is a “normally off / push on / push off” button.  I connected a wire directly to the positive power terminal of this switch.  I connected the negative power wire to the on/off variable terminal of the button.  From the on/off terminal, I also connected a wire to the negative terminal of the button’s led light, as well as a few extra modular wires.  The purpose of this is when the button is in the “off position” nether the button’s LED light, nor any other lights that are connected to the negative wires passing through this button will function.  When the button is pressed, not only will the power from the negative wire connect and illuminate the button’s light, so will all subsequent lights that are connected.  This was probably the most tricky part to figure out.

Here’s the wiring harness fully assembled, outside of the guitar body. 

 Proof of life #4 – Everything works as it should!  Note, this wasn’t the case the first time.  It took me about 10 minutes swapping wires to figure out which positives and negatives should be connected to make this thing work.  Patience is the key here, especially with so much going on.

Wow, is it pickup time already?  As mentioned previously, I chose to use a Dimarzio Blaze 7-String pickup in the neck, and a Dimarzio Evolution (Steve Vai designed) pickup in the bridge position.

One thing I hadn’t anticipated was how difficult it would be to source a 7-string humbucker pickup ring that met my specifications!  There are endless choices for 6-string, but for 7, the pool was very shallow.  Here’s a quick test to see if the damn thing fits. 

Here’s a shot of the Dimarzio Blaze, with the pickup ring installed.  Note – If you’ve never installed a pickup ring onto a humbucker, be prepared to curse a few times, at least… 

In order to obtain proper LED illumination, I wanted to wrap the LED strands around each pickup.  I quickly found, however, that this just didn’t look great in the final product.  In the end, I decided to place the pickups on top of the LED strands, to create an illuminated backlight effect.  This ended up working exceedingly well.

Here’s the bridge pickup in place.  It’s actually starting to look like a guitar body! 

And of course, I couldn’t resist laying the neck in place for a quick peek…

Here’s a shot of the lighting, with the neck pickup installed.  It’s coming together!

Next up, installing the bridge pickup.  This went in as easily as the neck. 

Finally, both pickups are installed, with the full LED lighting rig in place!  I’m not going to show a picture of how the lighting looks at this stage, as I’d rather create some suspense for the final build shots.  Enjoy!