Lighted T Project with a Twist

Lighted T Project with a Twist

I bought the lighted T several weeks ago and finally got around to installing it. Looks great! I wrote up the entire project at:

By design, mine stays on all the time at a low brightness (shown above), and automatically goes to high brightness when the headlines turn on. The power required for low brightness is an insignificant 5 mA. If the 12 V battery was not used for anything else, and not charged from the main battery, it would power the lighted T for over half a year (ignoring internal battery losses).

There are other ways to control when the lighted T is on, which I explain in the instructions. In all, a nice addition to my MS!

NKYTA | 12 avril 2014

Oh, now that is really cool!
+1 Tap!

LEvans | 12 avril 2014

I'm not a big fan of mods but this looks nice! Great job.

Rheumboy | 12 avril 2014

Lighted T, pretty cool but will replace lighted farts!

2196004393 | 12 avril 2014

Are there any Professionals who install this if this is something I would not do?

Pungoteague_Dave | 12 avril 2014

Very nice. I did the same thing with the BMW roundels on either side of my motorcycle's gas tank. They are wired to glow white all the time, and flash yellow with the turn signals.

I seems to me that you'd want the T to glow brightest in the daytime, and dim for nighttime use, based on relative visibility given ambient lighting conditions. I would do this mod, but can't see adding any unneeded electrical draw to a battery-powered vehicle, no matter how small.

NO2PTRL | 12 avril 2014


How can I get a kit, how much is it, and who would I hire to install it?

Bighorn | 12 avril 2014

The link to the kit is within the instructions link. I think it was $185.

Brian H | 13 avril 2014

Some have fire in their belly. Yours seems lower, and more posterior.

Gadfly | 13 avril 2014

I lost interest when I got to the "drill holes" bit.

Nuts4MS | 13 avril 2014

One question I have is that if you hook it to the DRLs does it stay on when the headlights come on? | 13 avril 2014

@Sterlingllc1: Where to buy and costs (about $185 for the Lighted T parts) are all in the linked page. Not sure where you could get someone to do the install for you. It is really just a DIY type project.

@Pungoteague_Dave: As for brightness, when it's dim, it is not all that noticeable during the day, but the dim mode enhancement was created specifically to not have any significant battery drain. Even full brightness is fairly low power (about 200 ma). In full brightness mode at night it shines almost as bright as the DSL. If it was dim at night, it wouldn't be that noticeable when the other lights are on. Hard to describe until you see it. It actually works quite well.

@Trekkie Not: I try to make any modifications so they can be undone with minimal effect, but this one does require two small holes in the nose cone. If you were to remove the lighted T, and put back the chrome emblem, it would cover the holes. At worse you can replace the nose cone quite easily (although about $450).

@Nuts4MS: If you connect it to the DSL, it does stay on when the headlights are on too.

NO2PTRL | 13 avril 2014

Ditto on the drill holes, just give me a flash light.

2050project | 15 avril 2014

Very cool... it's available to buy over on TMC: | 20 avril 2014

@2050project - It might not be clear, but I'm not selling the Lighted T, you have to get it from TMC. I have the link in the project, but thanks for also including it above.

After having it installed for a few weeks, I also like that it acts like a night-light in my garage so I can see in front of the car when it's dark. It's also even easier to find at night in a parking lot!

Fins | 23 août 2014

I'm about to install my lighted T is it worth all the extra work to have it lighted durning the day with the DRL or just have it come on with the headlights?

Option 1 comes on only when DRLs are on
Option 2 comes on with headlights
Option 3 comes on with DRL and brighter with headlights

Please advise what you have done and what you like | 23 août 2014

I set it up so it's on all the time (dim) and only bright with the headlights. In my description, this is option 3. It is not connected with the DRL.

Even though I put the switch in for different modes, I've never changed the mode. If I did the project over again, I'd just remove the switch. It takes so little power (especially in dim mode) that there has never been a reason to turn it off. It likely cuts the work in half too and gets rid of one connector.

I like that it is lit up in the garage, even though the car is "off".

Fins | 23 août 2014

So I'm a little confused you would have just connected it to the always on at the fuse box...?

If I'm understanding you correctly it would always be at its brightest point... And when you wake the car with your fob it would come on.....Correct | 23 août 2014

There are actually quite a few ways to connect it depending on what you want. There are some empty fuse slots that are always on (which is what I used and showed). If you want it to only appear when the car is "ON", use empty fuse slot F33 instead.

To make it "dim" when anything other than headlights are on, you'll need to use the two diodes and two resistors I show in the diagram. I just created a new diagram that shows how it is wired if you skip the switch, so that it remains dim unless the headlights are on.

I've updated the instructions to include this new diagram too.

Fins | 23 août 2014


Fins | 23 août 2014

You have been a lot of help but I have one more question/comment the 1N4001 diode keeps the duel power sources for causing a short.

Example if you touch two hots together you get a spark/short... (Lighted T will be connected to headlights and direct power) | 23 août 2014

Yep, diodes isolate the power. While my original diagram with the switch was correct, I did screw up the modified diagram earlier posted above. I've corrected it and the prior post is now fine as is the image on the TeslaTap website.

I also ran a quick test and confirmed the dim mode only takes 11 mA, which would run for years if there was no other items in the car taking power.

Fins | 23 août 2014


amirm | 24 août 2014

For those looking for a professional install in the SF Bay Area give me a call. I am organizing a group install and talking to several local installers.
Amir 650 269 4667

Charger | 25 août 2014

Why did you use two different sized resistors? Is it because one is for the top and the other for the T? Also can you eliminate one branch and combine the two light side red wires, under one connection like you did with the black? | 25 août 2014

The top and bottom portions take different currents. The bottom portion has many more LEDs and takes more power than the smaller upper portion. The resistors need to be different to provide a similar brightness level. This means you cannot combine the two "red" wires, or you'll end up with the top much brighter than the bottom (when going through one resistor).

Now if you go with the diagram above that doesn't have a switch, you can move the resistors and diodes to the nose cone, and have three wires from the nose cone connect to ground, always on power and headlight power.

jordanrichard | 25 août 2014

Ummmm doesn't this potentially void a warranty?

Charger | 25 août 2014

good information. Thanks for the quick update! :)

mdbuehler | 25 août 2014


With mods they have to show the mod caused the failure you are trying to get warrantied. Even then (sayit actually does cause a problem) it would only void coverage on the things it affected, not the entire car. I can't see how a couple fuse protected LEDs could cause problems. I'm tempted to try this when mine arrives :)