Debugging Guitar Wiring
So you’ve built your guitar, wired it up, plugged it in and….. Nothing. Well that is frustrating.
This guide is designed to help locate the issue and get the guitar sounding great.
The Signal Path
The signal path of your guitar generally follows one of two paths:
Frequently, debugging a misbehaving guitar is as simple as finding where the path is blocked.
While it may seem reckless, other than the pickup and the output jack, no other components in your build are required. So go ahead and bypass the switch and/or pots to see if things improve.
For instance, in a Fender style guitar, the pickups are wired to the switch. There is normally a wire in the center of the switch that goes to the volume pots. Move this wire so it connects the switch to the output jack. Add a ground wire between the components and see if things improve. If they do, you know your pots are either wired wrong, or need to be replaced due to an internal issue.
Similarly, bypass both the switch and pots by wiring the pickup directly to the output jack. If you have no signal at this stage, you either have it wired wrong or your pickup is bad. Try a second pickup if available to verify.
Once you know which components do work, add the other components back in one at a time.
Follow our handy Debugging Flow Chart to tackle components one at a time.
Grounding is a concept that can be confusing to beginners. You will see the grounds noted on the wiring diagram with this symbol:
The principle of grounding is simple: All the components (pickups, pots, switch, jack) have a ground. All these grounds need to be connected to each other in one way or another. For instance, if the pickups are connected directly to the volume pot, the bare wire (ground) of the pickup will be connected to the back of the pot. A wire will also be run from the back of the pot to the output jack. This ensures the ground has continuity from the pickup all the way to the jack.
It can be a tedious process to install all your components and string the guitar, only to have them not work. This is especially painful on Semi and Hollow Body builds. You can bench test your electronics beforehand by plugging the wiring harness into your amplifier. Make sure the guitar volume pot is turned up. Now lightly tap the pickup with something metal such as a screwdriver. If it is working you will hear a loud thud. Now you can install the components and string the guitar with confidence.