Aspiring tinkerers new to the wiring of a guitar sometimes get grounding confused at first. Often i see posts on forums and FB groups asking about grounding. But once you eliminate the hot wires from the drawings, it gets easier. You see easily how ground work. Ground is there to remove negative noise like hums and buzz. When it comes to grounding you guitar electronics, remember these rules: - Everything metal should be grounded (included any shielding done) not your Strap knobs though... - There is nothing wrong in over-grounding your components. (Ground loop is a myth and only exists in higher power installations. Guitar-electronics runs on microscopic voltage)
Lets talk shielding quickly (if i can) SHIELDING:
Does shielding work: YES: If you have lot of AERIAL NOISE around you... and YES if you play live on stage. NO: If you are a bedroom player.. Shielding is useless more or less. But that depends on your surroudings. Remember that shielding only blocks out aerial interference aimed at your guitar. Anything air bound noise coming at your guitar will come into your wiring and create noise. However, if - ...the electricity network in you house is dirty (badly grounded) - ...a large power transformator standing out side pumping power to your neighbourhood - ...your amp is not grounded or have ground issues.. Them shielding has ZERO effect. Why? Because the noise is coming trough the cables hooked up to your guitar, pedalboard and amp. It comes straight in to your jack cable. Remember that the essential 60hz cycle hum will ALWAYS be there, no matter what.
BUT... If you stand on a stage with a huge stage light rig behind you and other stuff transmitting signal, If you play in a band called U2 or Pink Floyd, even radio communication favours in, All this stuff bombards interference straight at your axe. Shielding will be a neat thing to have if you have all this coming at you. Encapsuling everything in a faraday cage (as they call it) will put your electronics in a prison. Just remember that your pickups will let some of that noise in since they are out in the open.. It will never be a 100% sealed cage Personally, i dont think shielding is that effective. That small patch of aluminum to shield the pots and switch you find in stock pickguards gives good protection enough to be honest. Remember that fully shielding the guitar can also alter the voice of your pickups as well. Back to grounding. A fully shielded guitar have its perks though. You can eliminate a few cables in the process if you have one. Here are som nice schematics i made with a few scenarios. No Shield, Partially shield and fully shield.. Time to Grounding your electric guitar and shielding it properly.
WIRING: NO SHIELD IN PICKGUARD. You rarely come across a Strat with zero shielding. Even cheap asian guitars has them. I am talking about the small shielding sticker in aluminum that cover the pots and switch only. But i will include it just to show that everything needs a ground-wire if no shielding is present.
Note: If you study this, especially how things travel to one place for then to go to the last palce. Basically, everything is joined together on the volume pot before they travel to the final destination that is the Jack socket.
ALTERNATIVE SPRING CLAW WIRING:
PARTIALLY SHIELDED:
This is with the stock aluminum shielding patch that comes with any pickguard you buy. The wiring is the same, but the pots and switch needs no wiring.
FULLY SHIELDED PICKGUARD AND CAVITY.
This is where it gets interesting, This scenario gives you many choices how to ground everything.
That concludes grounding. Now for Telecasters, its practucally the same. The ground to the bridge is attached to either the Humbucker brass plate or trough a hole that leads to the bridge itself. Expose some wire and screw the bridge firmly on top of it. If the cavities have conductive paint shielding (Black by color), You must krimp an o-ring connector to the cable and screw it in to the painted wood to make a connection. I recommend screwing them to the side walls in the routing and not the bottom floor. This is to eliminate screws coming trough the body to the back side. (is not as thick as you think).
This is a bad idea...
TROUBLESHOOTING: Correct grounded guitar will always make a noise (on single coils)
QUESTION: When you touch the strings on the guitar and the noise decrease/lowers noise. ANSWER: Nothing. Your guitar is wired correctly
QUESTION: I touch the strings and the noise gets worse
ANSWER: You ground is faulty somewhere. You need to diagnose. If you have a multimeter, check for continuity. Put the multimeter on continuity tester (The terminals beep when you put them together) Put one terminal on ground terminal on the jack socket and use the other to touch various other components. If you dont get a beep somewhere, you must check the ground going to that component. This can be a cold solder joint or a broken cable. If you have shielding, play around with the multimeter in there too. If you just wired the harness and put it to use for the first time, check if you did not reverse the ground/hot cables on the jack socket. QUESTION: Do i need to ground the strap knobs ANSWER: Uhhhhh.. no.. QUESTION: I have EMG Active pickups. Do i need to attach a ground from the claw to somewhere. ANSWER: No grounding needed to the claw. The rest of the circuitry is grounded in the PCB if you have the latest generation EMG with quick connectors. If you have the old type with soldered leads, you might need a ground. But it wont hurt to have one.