I was asked if I could fix a noisy Telecaster, I thought that was the idea!  However on listening there was an excessive amount of hum.  I though it would be less complicated as you can get to the wiring without taking the strings off.  However once I got it open I couldn’t immediately find anything wrong and there were a few extra wires that I needed to backtrack.  Oh well strings and pickguard off.

I’ve encountered a problem like this recently and found the live and earth reversed on the jack socket.  No they are correct.

It seemed like an earthing problem so a close look at that side of things first.  without too much poking about I found it.  All the earth leads from the pickups etc were terminated (not very neatly) on one tag on the pickup selector switch which wasn’t itself earthed.  It was earthed in that it and the volume & tone controls are mounted on a metal plate, probably OK when everything was new but with a little age and dirt the joint will have electrically failed.  I tidied up the one big joint and added an extra earth wire.  (see the red arrow below).

That did the job and should last.  Still noisy but only in the right way!