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Discussion Starter · #1 ·

I've studied quite a few TT installation instructions online over the past few weeks, and I've noticed something about them -- they all focus much more on the "fit and finish" of the install than they do on describing the actual wiring clearly and in detail. So I'm going to convey my experience with installing a TT on my B5. I'm only going to address the electrical component, because there are any number of How-To's that will explain how to fit your TT into one nook or another in your car's bodywork.

I have the Immobilizer 2, so I didn't have to worry about using the TT Buddy to auto-lock my car after the TT shuts the engine down. As such, I leave it to the creators and users of the TT Buddy to explain how to connect their product correctly. If anyone wants to add to this post with a detailed explanation of how to wire up the TT Buddy, including descriptions of the functions of each wire that needs to be tapped, it would be more than welcome.


You need to be able to perform the following tasks to install your TT:

· Use a screwdriver.

· Use a ratchet wrench.

· Use a wire cutter and stripper.

· Use a soldering iron.

· Use an electrical wire probe.

· Remove fragile plastic parts without breaking them, or at least have the money to buy new ones.

· Bend into funny shapes from time to time.

· Work in tight spaces without getting extremely angry.


You need to have the following tools and supplies to be able to install your TT:

· #1 Crosshead screwdriver with as long a stem as possible.

· Small flathead screwdriver. (Blade should be no more than 3/16" wide. A large jeweler's screwdriver is perfect for this, whereas a small jeweler's screwdriver is much too small.)

· 8mm hexagonal socket, and a ratchet wrench to use it with.

· T20 Torx bit with a 1/4" hexagonal base, and a bit driver to use it with.

· Cordless soldering iron. (Radioshack sells a butane-powered one for $20. It works great.)

· Silver-laced solder. (Radioshack also sells this. The silver improves conductivity, but it requires a hotter iron to work with. Some electric irons may not be hot enough.)

· Instant soldering iron tinner. (Helps keep the iron clean and working well.)

· 12ga. wire and 18ga. wire.

· Wire cutter.

· Wire stripper.

· Wire probe.

· European wire connectors with 8ga. capacity. (Radioshack sells these in strips. You'll want to cut them apart and smooth off the cut edges with a razorblade.)

· European wire connectors with 12ga. capacity. (The larger connectors are too large for some of the wires you'll be working with. Make sure to get both sizes of connectors.)

· Paper towels to wipe sweat with, and to clean the soldering iron with.

In addition, you need to have the following tools to be able to install the Immobilizer 2 bypass relay:

· Basic 4-blade Automotive relay. (Radioshack sells this part too. As far as I know, they offer only one Auto relay , and it’s the kind you want to get.)

· Female Flat Blade wire connectors suitable for 12ga. – 18ga. wire. (Once again, Radioshack sells these too.)

· Bolt-mount wire connectors suitable for 12ga. – 18ga. wire. (You really don’t want to just wrap wires around bolts and tighten them down, because the pressure of the bolt head will cut through the wire.)

· Wire connector crimper. (If you’re smart, you have one of those all-in-one wire cutter/stripper/crimper pliers.)


Based on my experience, the instrument cluster does NOT need to be removed in order to gain access to the ignition harness, contrary to what some other people have said. I was able to get at my ignition harness right at the ignition switch itself, though to get at it, I had to remove both halves of the steering column cover AND pull the square-doughnut-shaped molding around the steering column as far forward as possible without having to remove the steering wheel to do it. Needless to say, it was a tight fit, but it also meant I didn't have to cut into any harness webbing. I consider that a plus.

The instructions say to de-insulate a half-inch portion of each wire that will be tapped, and then to solder the matching TT harness wire onto it. This is a perfectly good solution, but I prefer to set up wiring that I can disassemble if I need to. (And based on my own experience, I definitely did need to.) That's why I said to use the European-style connectors instead. However, to use these properly, you need to cut and strip the ignition wires, and you ABSOLUTELY MUST SOLDER THE WIRE TIPS or else the copper braids will fray and break off when you tighten the connector screws onto them. Soldering them also increases the contact area, thus improving conductivity in the joints between the connectors and the wires.

It is possible to bypass the Immobilizer 2 alarm without using a relay, but that introduces the possibility of frying your CCM module if something goes wrong, because you won't have a fuse in the circuit anymore. Bad idea. Spend the extra ten bucks and do it right.


First off, there are two bundles of wires that you're going to have to deal with -- the ignition harness and the TT harness. Since there aren't really any premade VW harness adaptors for any of the major brands of timers (HKS, GReddy, Blitz), you're going to have to splice-and-dice to get your TT to work properly. You're also going to need extension wire (I used braided copper Monster Cable because I had it and because it's good-quality), as well as a cordless soldering iron, silver-laced solder (for better conductivity), and about fifteen European-style connectors. Why so many? Because some of them are bound to not work right, and you don't want to run out. You'll need two sizes of connectors: 12ga.-22ga., and 8ga.-18ga. You'll only need two of the larger kind, for the main ignition wires, and the rest of the connectors can be of the smaller size.

The wires coming out of the ignition harness are as follows:

2x 14ga. Solid Red: Battery power. These wires come straight from the battery. They supply power to everything else on the ignition switch.

1x 10ga. Solid Black: Engine power. This wire supplies power to the engine's electrical system, and has power whenever the ignition is in the "ON" position.

1x 10ga. Red/Black: Starter power. This wire supplies power to the relay that controls the starter. It only has power when the ignition is in the "START" position.

2x 14ga. Yellow/Black: Cabin power. These wires supply power to everything in the cabin besides the radio (which has its own electronic cutoff switch).

1x 22ga. Solid Red: Accessory power (aka Key Power). This wire supplies power to items like the window motors. It loses power when the key is completely removed from the ignition.

1x Unused Connector: This connector doesn't have a wire in it normally. For the record, it has power only when the ignition is in the "OFF" position. I'm sure there's a nifty use for this, but I haven't come up with one yet.

The wires coming out of the TT harness are as follows: (My colors are based on an HKS Type-0 model. The main wires should be the same for any TT, but the secondaries are probably different.)

1x 16ga. Solid Red: Battery power. This wire supplies the TT with power. No other power supplies are needed. (Don't be fooled by the blue Accessory power wire -- it does NOT power the TT, it lets the TT power other things!)

1x 16ga. Solid Green: Engine power. This wire allows the TT to power the engine after the ignition switch has been turned to the "OFF" position. Don't tap into this wire to power any accessories -- the engine electrical system by itself will tax this wire pretty much to its limit. Use the blue wire to supply power to accessories instead.

1x 18ga. Solid Blue: Accessory power. This wire allows the TT to power other devices besides the engine while it's counting down. This wire is optional -- only use it if you have something else that needs power. DO NOT CONNECT THIS WIRE TO THE ACCESSORY WIRE ON THE IGNITION SWITCH.

1x 22ga. Solid Black: Chassis ground. Every electrical system needs a ground -- this wire gets that job. Attach it to a convenient bolt on the frame of the car, but avoid using painted bolts because they won't conduct electricity very well.

1x 22ga. Grey/Brown: Handbrake switch tap. In cars with manual transmissions, you need to connect this to the handbrake switch to make sure that the engine will shut off instantly if someone tries to drive off with the car. In cars with automatic transmissions, you can bolt this wire to the chassis -- the Park/Neutral interlock will prevent thieves from putting the car in gear without the key. THE TT WILL NOT WORK IF THIS WIRE ISN'T CONNECTED TO ANYTHING – CONNECT IT TO GROUND IF NOTHING ELSE.

1x 22ga. Green/Brown: RPM sensor tap. This wire supplies the TT with a digital signal that communicates the engine RPMs, so it can more accurately calculate how long to set the countdown for. This is an optional connection, as the TT can also estimate engine RPMs according to oscillations in the 12volt power coming in from the alternator. If you don't use this, just cap the wire off or dip the end of the wire into a bottle of clear nail polish.


Assuming you have all the supplies you need, and you've removed the steering column covers (taking the bottom one off is tricky, but with a thin screwdriver you CAN remove the screws behind the steering wheel if you turn the wheel to just the right angle), then you're ready to start cutting and stripping. You'll need to cut the plastic plug off the end of your TT, and you will want to strip and solder every wire coming out of the TT harness. You may also want to splice one of your smaller Euro connectors into the black ground wire, so you can attach other grounds to it without needing to buy extra bolt connectors like what the ground wire has on it. Once you've got all of the TT harness wires stripped and soldered, install one of the small Euro connectors on to the end of each wire. Now you're ready to move on to the ignition.


The ignition wires you need to cut, strip, and solder are as follows: (Make sure to strip and solder BOTH of the cut ends of each ignition wire.)

1x 12ga. Solid Red: Battery power.

1x 10ga. Solid Black: Engine power.

If you're going to be installing the Immobilizer 2 bypass relay, you also need to cut, strip, and solder the 22ga. Solid Red wire (Accessory power). I don't know if you need to strip this wire to use the TT Buddy, but if you're not going to do anything to your alarm system, then you should leave this wire alone.

Once you've prepared the Solid Red and Solid Black wires, install one of the larger Euro connectors onto the end of each that comes from the ignition switch. Clamp these as tight as your screwdriver can handle -- you don't want these coming off. If you're going to install the Immobilizer 2 bypass relay, install one of the smaller Euro connectors onto the ignition switch side of the 22ga. Solid Red wire. Don’t connect the other ends of the cut ignition wires to anything yet.

You're done messing with the ignition wires for the time being. Go install your TT into whatever nifty place you've found for it. Then go inside and prepare two pieces of 12ga. extension wire, stripped and soldered at each end, that will be long enough to reach from the end of the TT harness to the ignition switch. (If you're going to connect the optional extras on your TT, you need to make extension wires for them too. Use the 18ga. wire for these.)


Once your TT is installed and your extension wires are ready, it’s time to complete the connections between the ignition harness and the TT harness. If you’re anything like me, wiring is incredibly hard to get right without drawing a diagram first or at least reading very detailed instructions, so I’ll try to be as clear as possible.

1. Connect the TT’s Ground wire (Solid Black) to a convenient unpainted bolt on the frame of the car.

2. If you’re going to use the TT’s Handbrake Switch Tap (Grey/Brown), use the wire probe to determine which of the two wires connected to the handbrake switch has power ONLY WHEN THE HANDBRAKE IS ON, and connect the Handbrake Switch wire to it. If you’re not going to use the Handbrake Switch Tap, then connect it to the same bolt as the Ground wire.

3. Connect your two 12ga. extension wires to the Battery Power and Engine Power wires on the TT harness. MAKE SURE YOU REMEMBER WHICH EXTENSION WIRE IS WHICH. If you’re going to use any optional extras on your TT, connect their extension wires as well.

4. Route the extensions wires through the inside of the dashboard and pull them out through the left side of the steering column opening.

5. Take the TT’s Engine Power extension wire and mash it together with the Engine Power wire (Solid Black) coming out of the ignition harness using a pair of needle-nose pliers. Once the two wires are a little more comfortable with each other, push them both into the empty side of the Euro connector attached to the other cut end of the Engine Power wire coming out of the ignition switch. Tighten the screw on the connector as much as you can.

6. Take the TT’s Battery Power extension wire and the ignition harness’ Battery Power wire (Solid Red) and push them bothin to the empty side of the Euro connector attached to the other end of the Battery Power wire coming out of the ignition switch; you shouldn’t need to mash these two wires together first, they should fit just fine the way they are. Tighten the screw on the connector.

At this point, the basic TT installation is complete. If you’re using any optional extras on your TT, you should connect their extension wires now. My TT didn’t have any optional extras, so I can’t offer any assistance on connecting them, except to follow the one-wire-in, two-wires-out approach to splicing the wires together with the Euro connectors.

If you want to install the Immobilizer 2 bypass relay, continue to the next section. If not, go ahead and fire up your car to test the TT’s operation, and if all is well then start to button up the dashboard again.


This little addition to your TT will give your install that extra bit of polish, because you’ll be able to lock your car and arm the alarm while the engine is still idling. (Very slick.) Note that this only works on cars made before 2002 – more recent cars have a more sophisticated alarm system that requires a TT Buddy (not described here) to auto-lock the car once the TT shuts the engine down.

The first order of business is to prepare four more extension wires, approximately 18 inches apiece, using the 18ga. wire you have left over from the TT installation. This time, in addition to stripping and soldering the ends of all four wires, you also need to attach a Female Blade connector to one end of each wire using your wire crimper. (You can also solder the connectors on, but it’s not necessary – this circuit won’t use much power.) Take one of the four wires and attach a bolt-mount connector to the end that doesn’t have anything on it yet. This will be the ground wire for the relay.

Now you have to go cut more wires inside your car. If you planned ahead when you were cutting and stripping the wires coming from the ignition switch before, then you’ve already prepared the Accessory Power wire (22ga. Solid Red) by cutting it, stripping both cut ends and soldering the ends to give them strength. If you haven’t done this yet, do it now. Once the Accessory Power wire is ready, attach one of the smaller Euro connectors that you have left over from the TT installation onto the end of the wire coming from the ignition switch. Insert one of the four relay extension wires (NOT the one with the bolt-mount connector on it) along with the other end of the Accessory Power wire into the empty side of the Euro connector and tighten the connector.

Next you need to open the fusebox on the left side of the dashboard. Removing the outside panel is fairly easy – just pry it open with your fingers, and grease the metal clips holding it in place so you’ll be able to remove it more easily next time. Removing the back panel is trickier. You have one of two options: you can unscrew a couple of 8mm hex bolts holding the fusebox in place so you can tilt the fusebox out of the side of the dashboard and pop the back cover off, or you can do what I did and leave the fusebox in place, using a thin screwdriver to reach between the fusebox and the dashboard frame to pry open the plastic clips that hold the fusebox’s back panel in place. Either way, you need to remove the back panel.

Once you’ve got the back panel of the fusebox off, find fuse #6 on the top-left side of the fusebox and poke it to make it wiggle. Look behind the fusebox and grab hold of the wire that moves when you poke fuse #6. Having isolated this wire, cut it and strip and solder both cut ends. Install two of the smaller Euro connectors, one connector per wire. Go get the remaining two relay extension wires that don’t have bolt-mount connectors on them. Connect each wire to one of the two Euro connectors you just installed. REMEMBER WHICH WIRE CONNECTS TO THE FUSEBOX. You can put the fusebox back now – reinstall the back panel if you want to, but it doesn’t make a huge difference either way so long as your extension wires are long enough.

The final step in the installation is to plug the relay extension wires into the relay, and to attach the relay to a convenient location. Don’t attach the relay first, because you need to see the numbers next to each terminal on the relay to connect it properly. The connections you need to make are as follows:

Terminal 85: The ground wire with the bolt-mount connector on it. (Attach the other end of the ground wire to a convenient bolt somewhere nearby.)

Terminal 86: The wire connected to the Accessory Power wire (22ga. Solid Red) on the ignition switch.

Terminal 87: The wire connected to fuse #6 in the fusebox.

Terminal 30/51: The wire that used to be connected to the fusebox before you cut it off.

With these connections securely in place, find a bolt somewhere in the vicinity of the fusebox and attach the relay to it, or use a piece of two-sided sticky foam tape to attach the relay wherever you want. If you’re wondering whether you can attach the relay to the front of the dashboard frame in the indentation between the crash-brace mounting and the steering wheel, the answer is yes, you can fit the relay there and the dashboard kick panel will still fit.

That’s all there is to it. Now you have a turbo timer to help you avoid clogging your turbocharger with oil tar, and you have a relay that will fool the alarm system into thinking the car is off when the engine is cooling down. All that’s left to do is reconnect the negative battery terminal, turn the ignition on and wait for a few minutes while the throttle body learns how it works all over again, and finally, start the car and see if the TT kicks in. If it does, then shut the car off, pull the key out of the ignition, close the door, and test the alarm bypass. If you can lock the doors before the engine shuts off, everything is working well. You’re done!

2006 Shawn Elliott

8,975 Posts
Discussion Starter · #2 ·
Here's my take on the installation of a turbo timer. Note the focus on the wiring aspect of the installation as opposed to the aesthetic aspect. I had no problem putting my TT where I wanted it (and everyone wants it someplace different), my problem was getting it hooked up right. So hopefully this will help someone else get it right the first time instead of spending days working on it.

Founder of the STFA
8,667 Posts
Lots of good details.

Now I know for sure why I never installed a turbo timer.

8,975 Posts
Discussion Starter · #6 ·
Lots of good details.

Now I know for sure why I never installed a turbo timer.
It really is pretty easy once you know exactly which wires to connect.

Sorry I couldn't provide any pics; my digicam is shitty and there's no way I'd get good clarity in the kind of lighting I had to work with. Maybe I'll scalp some pics from other writeups and mix them in with the writeup. With proper credit, of course.

2,332 Posts
It really is pretty easy once you know exactly which wires to connect.

Sorry I couldn't provide any pics; my digicam is shitty and there's no way I'd get good clarity in the kind of lighting I had to work with. Maybe I'll scalp some pics from other writeups and mix them in with the writeup. With proper credit, of course.

So, how are those pics comin?:D
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