Add a Bluetooth Adapter to Your GPS Device




I needed a way to hear my cheap a$$ GPS under the helmet on my motorcycle and didn't wanna fork over 2x the price for a "motorcycle ready" GPS device so I made it myself.
This may be interesting to bikers a well!

You can also find it here:

GPS + bluetooth

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Open It...

When you CAREFULLY open your new TomTom One you'll notice that there is a battery and a speaker on the back and all the electronics on the front side.

Step 2: Radio Shack Bluetooth Adapter

Buy a bluetooth adapter for non-bluetooth cell phones like this one from RadioShack ($30) that even comes with an adapter for nokia phones with a tiny receptacle 2.5mm headphone jack!

Step 3: Drill a Hole...

Drill a hole in the bottom of the back really close to the back wall. You have about 12mm to the battery so be real careful.

Step 4: Connect...

Duplicate the two wires going into the speaker and connect them to that small phone jack and glue it to the back wall after you stick it through a hole you just drilled.

You can do this by using a new two pin molex connector. Just attach two more wires to it.

Step 5: Plug In!

When you put it back together it will look like the jack was there straight out of the factory.

Step 6: Use With Your Cell Phone Head Piece

Now you're ready to pair it with your cell phone bluetooth ear-piece and use it under the helmet.It works awesome!You just made your self an upgrade to a $300 more expensive device that you can mount on your motorcycle.

Enjoy not getting lost!

Park Tool Bike Month

Runner Up in the
Park Tool Bike Month

Be the First to Share


    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest
    • Robotics Contest

      Robotics Contest

    30 Discussions


    3 years ago


    This is a very fine piece of work,BUT have you tried to use your TOMTOM outside-especially in the sunshine-the display is almost invisible ! As I normally work with 'voice commands' I have just connected my earphones up inside as you demonstrated your v


    8 years ago on Introduction

    i got a garmin 265wt gps for Christmas and want to connect it to my motorcycle helmet intercom (starcom advance) problem is i have no audio out plug on the gps ?? couldnt i do this same thing on my gps and then get a male to male cord so i can hear the voice from the gps ooooooorr should i try and make the intercom a bluetooth like the gps ?? the intercom has audio input plug already anybody please hep me ooooo hep me please


    9 years ago on Step 6

    IF the gps has an audio out socket included is there anything i can buy to make it have bluetooth


    9 years ago on Introduction

    But how can I simply make bluetooth as a switching device??


    10 years ago on Introduction

    I've been riding around and just hating always having peek down at the screen (since i cant hear anything) very simple, GREAT IDEA!


    10 years ago on Step 1

    Excellent project. Just did this with my Navman S35 GPS. Worked perfectly. Many thanks for the idea. Phil in Adelaide, Sth Australia


    10 years ago on Step 1

    I'm a do I get my Tom Tom to come apart? Are there any tools I need to open it


    10 years ago on Introduction

    Great Idea! It's funny all the "why not do it this way or that " comments you get from people that partially read the instructable or they just think they can do it better, when in fact they can't even sharpen a pencil to a point. I like all the Instructables whether they are great or good, at least they are thinking and doing. That old saying 'money talks and BS walks" could be changed to "Instructables talk and BS walks" Great job to all that have Instructables and keep it up, I enjoy seeing them all, and sometimes building upon the original idea!


    11 years ago on Introduction

    This is interesting because: A: I recently modified my Mio C230 GPS to have an external speaker jack and B: I own one of these BT modules. The only problem is that I don't think they play nice with Motorola BT headsets as you need to enter a security code or something. Either way it's an awesome idea and I'll have to drag that stuff out to play around with it now! Thanks! :D

    2 replies

    Most often, if a security code isn't chosen by the user, it's: 0000 (four zeros). It's been the case with any of the bluetooth headsets I've owned.


    11 years ago on Step 6

    So, doesn't this model of tomtom include an audio out socket? Couldn't you just buy a model that has one ? I bought 4 in Dec. 2007, and all had headphone sockets. Did you show how to wire the switch connection on the socket, so, when you don't have anything plugged in, then the sound is routed to the internal speaker ? Or is it so that you will never hear the internal speaker again ? Why not dismantle the Bluetooth device, and fit it inside the case ? Surely it can be made to fit. One of my GPS units has an FM radio transmitter. So I'd need to have a tiny tiny FM radio earpiece.

    1 reply

    Reply 11 years ago on Step 6

    Weeeell, if it did have an audio out why do you think I would wanna make my own? No, the model I purchased for $300 in 2006 did not have that. Nothing is routed and there are no switches in my mod, signal is just doubled and you can still hear the speaker. That is if you're not flying down the highway on a motorcycle. If you can make a mod with the switch I would welcome that. Why not dismantle the Bluetooth device? Surely it can be made to fit??? What makes you claim such thing? It would be nice of course, but two things: 1. It surely CAN NOT fit 2. Even if it fit, the converter from the GPS device power to Bluetooth power would not. I did not understand the last thing with FM ?!?

    This is awesome. I don't have a GPS unit but I can see this being super useful for hacking anything with a speaker. Thanks!


    Reply 11 years ago on Introduction

    That is a Cardo Universal BTA II - bluetooth adapter for non-bluetooth cell phones. I don't think radio shack carries it anymore, I bought that one for it's size
    (and it was on clearance!) but you can really use any adapter for non BT phones.
    They all have a 2.5 mm plug (2.5mm receptacle is often found on cell phones) so once you have your GPS drilled and the receptacle in place you can plug any adapter.

    BTW I still have two additional plug receptacles left if you need it. Manufacturers of parts like this usually sell them in gazillions so if you write to them and ask for a sample they will send you few free of charge. :)