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Home : Trade Secrets Archive : Issue 162, "I wired this guitar, but it didn't work. Can you fix it?"
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PartsEven though I do guitar repairs professionally, I like it when players work on their own guitars. It’s good for guitarists to know about maintenance and to experiment for themselves on upgrading components.


Erick gets a phone call If they feel comfortable with setup and electronics work on an inexpensive guitar, I say go for it. It doesn’t really cut into my repair business: if they get into hot water they’ll bring me the work anyhow.
That’s what happened with this Les Paul Studio model. The owner, Jon, decided to swap out the electronics himself. He followed a wiring diagram, plugged it in and got... nothin.’ No sound. So presto, I’ve got the job.
I couldn't quickly find where he went wrong, so I decided it would cost me less time to rewire it than to troubleshoot it. A total rewire also gives me peace of mind, too: when every joint’s made by me, I can stand 100% behind the work.
See our Trade Secrets archiveTicking clock
Les Paul wiring Let’s pull the wiring and get started. Since I was gutting the guitar anyway Jon asked me to drop in a new set of Parsons Street humbuckers and wire the circuit the same way Gibson did in the ’50s. (As a side note he also wanted a Bigsby B-5/Vibramate setup installed while I had the guitar apart.)
Jon had also shielded the control cavity with copper foil; let’s talk about that:
To shield or not to shield?
Jon did a nice job of lining the control cavity with copper foil. That’s good for cutting back on 60 cycle hum from electrical interference. And in these days of cell phones, computer monitors and whatnot, we have more sources of interference than ever.
This humbucker-equipped guitar really didn’t have problems with 60 cycle hum. And the goal of this rewire is to create a more ’50-like guitar, so we decided to strip out the copper foil after all.
Les Paul shielding canIs this a good idea? After all, on some Les Pauls, Gibson even went to the trouble of shielding the electronics in metal cans inside the guitar — like the ’81 LP Custom in this photo.
I’d say the question of whether to shield is a judgment call. Since the idea behind Jon’s rewire job is “back to the ’50s roots,” he decided to go commando, shielding-wise. That works for me; I'll bet the old Les Pauls responsible for the recorded tones I love most were unshielded.
To wire up a true-to-50s circuit, I followed the diagram that’s included in the instructions for our Parsons Street humbuckers.
 
Prepping wires Prep the wires
I used single conductor shielded wire for most of the work. Three lengths were needed: about 12" for the run from the neck pickup volume pot to the switch, 13" from the bridge volume pot to the switch, and 16.5" from the switch to the output jack.
Shielded Push-back Wire
Color-coding wires Color-code them
To avoid mixups, I colored both ends of the pickup leads with Sharpie markers. I use red for the neck pickup and blue for the bridge. This way, when I push the leads through the channel into the control cavity, I know which is which.
 
Link to see video
Erick soldering Add a ground jumper
Using a 4" section of push back wire, I strip back enough insulation to allow 2-3 wraps around the neatly bundled lead wires.
Ground jumperI solder this to the braided shield to have one neat grounding wire for soldering to the switch.
Vintage Push-back Wire
wiring diagram

Wire up the switch
Follow your color key on the lead wires and solder it up!

Straight Toggle Switch
Imported switch Some imported LP style guitars have a wiring channel that’s too narrow to fit the bundle of 3 braided leads. In that case, use our four-conductor lead wire to connect between the pots, switch and jack.
4-Conductor Circuit Wire
Erick soldering Rewiring the controls
I put the pots into a wiring jig I made for Les Pauls: a piece of pickguard plastic with holes to match the LP control arrangement (cardboard works just as well). This lets me do my wiring outside the body, and everything fits back in neatly.Les Paul wiring removedThe guitar’s controls were on a metal mounting plate. We decided to ditch the plate, sticking with the ’50s theme.
 
The 500K CTS pots Jon used were in fine working order, so I cleaned them up and reinstalled them following the 50s diagram for our Parsons Street humbuckers.
With the circuit wired up I dumped the harness into the guitar and secured the pots.
CTS Control Pots
Three leads Before doing any soldering inside the cavity I installed the pickups and trimmed their leads to length. Now it's time to wire the pickups and switch to the harness.
Here are the shielded leads snaked through into the control cavity.
 
Output lead First I soldered up the outputs of the pots to the switch, then the pickup leads to the inputs on the pots.
The final step is to run the output from the switch to the jack. I reused the guitar’s black insulating tube, but if I didn’t have that a length of heat shrink tubing would have done the trick.
Heat Shrink Tubing
Done! Ready to rock!
Jon's guitar is wired up in the ’50s fashion, and much cleaner to boot! Now to give it a test drive.
 
Erick test-driving Encouraging my customer to do the work himself could have cost me an installation job and the profit from parts sales, but it worked out in the long run. Jon was happy to get some experience, and I'm happy to get his business!
 
   
Problem-solving products for this kind of work:
CTS Control Pots
First choice for long life and smooth response. 250K and 500K-ohms.
Golden Age Parsons Street Humbuckers
Authentic PAF specs, sweet vintage tone. Wake up your guitar!
Shielded Push-back Wire
Single conductor with braided shield, supplied in an economical roll.
More More More
Bigsby B5 Vibrato
For solidbody guitars with a flat face.
Guitar Nutdrivers
No more fumbling through your socket set for the right wrench!
Jack The Gripper
Holds a standard 1/4" jack steady while you tighten or loosen the nut from the outside. A real work saver!
More More More

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