Support / Fender Precision Bass Wiring Diagram & Fitting Instructions

Fitting Instructions

The good news is the Precision Bass is one of the more simple guitars to replace the wiring harness, because the harness is attached to the pickguard, which can be removed and worked on with ease.

Removal

Find somewhere safe, dry and secure to place your P Base guitar while you work on it.
Remove Strings.
Undo the screws that hold the pickguard to the body.
Carefully lift the pickguard up and cut all wires from the body to the pickguard closest to the pots. (normally a ground wire or two coloured black)
Put the guitar safely out the way for the time being.

Replacement

Working on the pickguard, cut the 2 x pickup wires from pot, leaving the wires as long as possible.
You should now be able to remove the 2 old pots and jack socket from the pickguard.
At this point you may want to clean the front of pickguard where the old pots have been.
You will need to check the size of the holes for the pots and jack socket as on some pickguards they are drilled small for cheap electrical components. If they are small, the best way to enlarge them to 10mm to fit CTS pots, is to use a round file.
The pickguard is now ready to fit the new harness.
From here everything is in reverse using the wiring diagram below.
Fit the new wiring harness into the pickguard.
Solder the 2 x pickup wires to the new volume pot (refer to wiring diagram)
The pickguard is now ready to go back into the guitar.
With the pickguard resting next to the guitar, solder the ground lead(s) to the pot. (refer to wiring diagram)
Fit the pickguard back into place, but don’t screw it down yet.

Testing

Plug the guitar into an amp and with something small and metal you should get a response from the pickups by gently tapping the pickup poles/posts. – Or you may have a Multimeter.
If Everything is working, screw the pickguard into place and re-string.

Tools & Equipment