Installing a new “input” jack on your guitar can seem like a job best left to a professional, but it is actually a relatively simple procedure that you can do yourself if you wish. The phrase “input jack” is actually a misnomer because it is technically the guitar’s output jack. Regardless of the name given to it, it is the only jack on an electric guitar. Some guitars have cover plates over the top of the output jack, but many simply have the jack pushed directly into the guitar body.
Locate the space on your guitar’s body for the output jack. Look on the side of the guitar’s body, roughly underneath the bridge, to find the jack. Guitars such as the Fender Stratocaster will have the jack underneath the bridge on the main face of the guitar, and these will often be covered by a metallic cover place. Unscrew the cover plate, if necessary.
Remove the old jack, if necessary. Remove the nut and washer by accessing your guitar from the back panel. On Stratocaster-style guitars, the pick guard must be removed to access the guitar's internals. Pull the jack outward to remove it. Remove any wires attached to the long and short terminals on the jack, and note down which color was attached to which terminal. This will help when it comes time to reattach your new jack.
Remove the nut and washer from the new input jack. Attach the relevant wires to the same points on your new jack. The wire from the middle terminal on the volume control should run to the “tip” (small) connection on the new jack, and the wire from the ground point of the volume control should attach to the medium length connection on the jack. Solder these wires in place.
Test out the jack by inserting your guitar wire into it and connecting it to an amplifier. Be careful not to touch any of the connection points on the jack while they are exposed, as the shortest and longest of them are “hot,” and will shock you if you touch them with the cable inserted.
Insert the new jack into the space in your guitar’s body. The electronics are now correctly connected, so the jack must simply be inserted into place. Go around the back of the guitar and place the washer on the opposite end of the jack. Screw the nut back in place so that the jack stays firmly in place. Replace the cover, if necessary.