How to Guide - Fitting a 3-way Pre-Wired Harness to a Telecaster!

A very long overdue 'how to guide' post here today looking at the step by step process of installing one of our Signature Series 3 way Telecaster wiring harnesses! Telecasters are an iconic modular design, making them very easy to work on, but I hope this guide helps you during your harness install if it is a new task to you. Here I will break down each and every step during the install process including removing the original wiring and installing your new harness. For this example, I will be retaining the original pickups but very similar steps would follow if you were to be installing new pickups and a harness at the same time. I will write a post about swapping pickups on a Telecaster in due course though too!

Let's start off with what tools you will require. I will also list below it some additional items that could be required depending on your guitar's original specs. Some far east made Tele type guitars for example may have pots with a smaller shaft diameter, in those cases you may choose to replace the control plate with a US spec item that would suit the new CTS pots, or you may choose to modify the existing plate. The CTS pots used in my wiring harnesses have a 9.5mm diameter threaded shaft, so you will need holes in your control plate that will accommodate for that. If you are choosing to widen the holes in your original plate, then I recommend doing this with a step cutter drill bit. If at all unsure about drilling the original plate, then a new US spec control plate may be the easiest option for you too. With that said, here are a list of recommended tools to have at hand during this install!



- 40w minimum Soldering iron
- Lead free solder (I personally use Rapid 22SWG Lead-free 0.7mm diameter solder)
- Cross head screwdriver
- Small flat head screwdriver
- Wire cutters
- Wire Strippers
- Small nose pliers
- 13mm socket
- Cloth or similar to protect body/paint finish
- Wiring diagram to follow, you can find all of the wiring diagrams on my website or by clicking HERE

Additional tools that could be required depending on your guitars original specs
- Step cutter and drill
- If replacing or adding a bridge ground wire, a length of 22AWG wire

1) Onwards with the install. Before the soldering iron is on, we'll want to strip the hardware and components no longer required from the guitar. 
As I'm not swapping pickups on this guitar, I don't even need to remove the strings to carry out the install, so we can kick things straight off by removing the control plate. This is a simple task of grabbing your cross head screwdriver and removing the two small mounting screws at either end of the control plate.


Helpful tip, have a small tub to hand so when you remove any screws etc you can keep them safely stored until required again.

2) We can now lift out the harness complete on it's control plate, and this is the first chance to see what original components we're working with. This Mexican built Telecaster has fairly high quality components already in there from the factory, some lower spec CTS pots and an Oak switch most notably. It does look like a whole bunch of spaghetti with the extra wire though! Will be nice to tidy that up a little in the process of the new install.

3) Next up I'll be removing the jack socket, which on this particular guitar is held in place by a traditional Telecaster cup mount. To remove the jack, simply grab your socket and loosen the securing nut.



4) With that loosened, you will then be able to simply pull the jack through the jack cavity into the main control cavity as shown in the image below. 



5) Now I move my attention to removing the various pickup and ground wires soldered to the pickup selector switch and pot casing. First up, I'll be removing the 'hot' connection pickup wires which are attached to two lugs on the switch. On this guitar, the neck pickup and bridge pickup have different coloured 'hot' leads which makes identifying them that little bit easier. Rather than un solder them from the lug, I simply chose to snip the wire. I personally find this a little less fiddly to do, but you can do either depending on your preference.



At this stage I will also mention that on this particular Telecaster, the pickup wires enter the main control cavity via two different access holes, so again this does make identifying which pickup wire is which a little easier. Some Telecasters have both pickup wires entering the control cavity via one access hole so it could look ever so slightly different to my images here but the general approach is the same.



I then also remove both of the pickup ground wires which are usually found soldered to the back of the volume pot casing. Again, you can heat the existing solder joint and remove them, but on this occasion I simply snipped the wires at the joint as I'll be tidying all of that up on the new harness install anyway.

6) Removing those wires will now mean you can lift out the old wiring harness and control plate completely from the guitar body. At this stage, it is the simple task of removing the old wiring from the hardware and installing the hardware onto the new harness. Again, I'll point back to something I mentioned in the opening paragraph. We are lucky on this occasion to be working on a Tele which already had CTS pots with a 9.5mm pot shaft thread diameter meaning I don't need a new control plate or don't need to widen the pot holes to accommodate the new harness. But if you do need to widen the pot holes, this is the stage where you'll need to do this, and I would recommend doing so by covering the plate in a masking tape or similar to protect the plates finish then by using a step cutter drill bit, widen the hole to accommodate the 9.5mm CTS pot shafts.





As you can see from the above photos, you'll require your small flat head screwdriver to remove the control knobs providing they are the traditionally used grub screw fixing type. Then your socket to remove the securing nuts, and finally a cross head screwdriver to remove the switch from the plate. The switch tip should just pull away with ease. 





In this series of photos, I simply show the process of mounting the new harness to the old hardware. Just a reverse sequence of what is explained previously. I will add however, that I personally recommend keeping hold of your wooden mounting board that I supply my harnesses mounted to for shipping, as you can mount your old parts to that board for safe keeping! Much better than just throwing it away.

7) Onwards with the install! I personally start this process by installing the jack socket first. Push the jack socket through the main control cavity and through the jack channel, mount it to the cup surround and fix in place with the securing nut provided. You may find that the Pure Tone multi contact jack I use with my harnesses protrudes a little further than the original may have, I personally like it sitting a bit more proud but if you like it more flush, simply add an additional nut or spacer behind the mounting cup.



8) Here I will be preparing the wires for soldering to the relevant places. The original pickups on this guitar are traditional 2 conductor wires (one 'hot' and one ground) with a plastic coating. You may have pickups that are cloth covered or perhaps 4 conductor too. If the latter, consult with your pickup manufacturers documentation to find out which wire is which. If they are cloth covered, you can skip this wire stripping stage as you can simply 'push' back the cloth to reveal the wire ready to solder which can be a lot easier to work with. But back to the plastic coated ones on this install..




This particular telecaster had a plastic coated wire coming from the bridge, this is because the original bridge pickup doesn't have a baseplate meaning it needs grounding with a separate wire. So here I have twisted it together along with the ground wire from the neck and bridge pickups, you might find it easier to make one ground solder connection than trying to handle three separate pot casing solder joints. Again, personal choice but I'll show it with them twisted together for this occasion. 



As the pickup wires on the original pickups are stranded core, I opt to 'tin' the wire to help with their install. I do this simply by twisting them tightly and applying a little solder to the wire core. Some pickup wire, like the cloth covered wire used on McNelly Pickups for example is pre-tinned so you wouldn't need to do this for those. 

9) On with the first solder joint! I'm going to start with the ground wires first. As I have twisted them together on this install example, I only have one ground solder joint to make and I've opted to do this to the back of the volume pot casing. You could of course do this on the tone pot casing too, either is fine.



10) Moving onwards, I will be soldering the bridge pickup 'hot' wire to the relevant switch lug. This really is the first step where you have to consult your wiring diagram. Check which lug on the switch this wire will be soldered to, and make your connection!


A little tip here, I tend to bend the wire onto the lug, this keeps it in place whilst you can wield your soldering iron and solder.



11) With the bridge pickup wire finished, onward with the last solder joint on the install, your neck pickups 'hot' wire. This again is done at the switch, so consult your wiring diagram and attach it to the correct lug.




12) With the soldering complete, before I screw everything back down for good, I simply flip the plate over and quickly plug the guitar in to check it operates as it should. I check each pickup position, and adjust the volume and tone pots in each of those positions to ensure it all operates as it should. If something doesn't seem right, like switch not working in the right orientation etc, you will need to check against your wiring diagram that the pickup wires have been attached to the correct lug and if you have any excessive buzz, double check you have a clean ground solder joint. There are some useful troubleshooting tips mentioned on my 'Home of Tone wiring harness fitting guide' which may be of help too. But hopefully, all was well and you can fix the control plate down and enjoy your handy work!




There we have it! The Tele 3 way wiring install is one of the easiest, and that ultimately is down to Leo Fender's genius modular design of the Telecaster. I really hope this helps with your own install if it's a task you've not carried out before. Upgrading your old wiring harness can offer great results, particularly if the original components are of low quality. It can bring out the best in your pickups, or allow for more usable controls when playing for a more expressive experience. 



Thanks again for choosing one of my wiring harness for your Telecaster, and I hope this article helps your install go as smoothly as possible! I'll soon also be posting a 4-way wiring harness install which will also include how to install new pickups at the same time.

You can find the range of 'Signature Series' wiring harnesses on the shop by clicking HERE
You can find the range of wiring diagrams and info guides to follow during the install by clicking HERE

James