How to install bluetooth in any radio

  • Illustration by Parquerama
Date:13 January 2014 Tags:, , ,

You can stream music through your radio and keep that original-equipment look – for less than the cost of a new receiver. By Murilee Martin

Bluetooth audio is common in new cars, but if your ride is a few years old, you might not be able to stream audio through the radio. Other options exist: your car may have an auxiliary input that connects any audio source via a 3,5 mm mini-jack; older cars might even take a cassette adaptor. But both of these solutions add clutter to the interior. Here’s a cheap way to put wireless audio in any car without adding unsightly cords or even changing the appearance of the factory audio system.

Wired FM modulator: Be sure it includes antenna connection cables as well as a power switch. iSimple’s IS31 Antenna Bypass FM Modulator has everything you need for about R300, but we found plenty of generic models on eBay for under R250.

Audio input cable: 3,5 mm stereo male to dual RCA stereo male. Stores sell these for less than R100. You can find them online for even less.

Bluetooth A2DP adaptor: Look for one with a 3,5 mm input and USB charging. A good example is the EDUP EP-B3503, which goes for about R240. Again, no-name units can be found for less on eBay (we found a Chinese made one for R52).

USB car-charger adapter: This charges the Bluetooth adaptor. Don’t pay more than R50 for one online.

Zip ties: For gathering up dangling wires.

Splice connectors: We like this style of connector because it’s almost fool-proof, ensuring that you have to do the job only once.

Tools: Aside from the basics (screwdrivers, spanners), you’ll need a voltmeter or 12-volt circuit tester and wire strippers.

The general concept is simple, but you need to be comfortable with taking your interior apart and working under the dashboard. Here’s how it’s done.

Remove the radio:
Disassemble the necessary trim and pull the stereo out of its mount to expose the rear of the head unit. This may require a specialised stereo-removal tool. For help on this, consult your car’s service manual or check online forums. Take pictures of the process so you can put things back together in the correct order.

Connect the modulator:
Remove the antenna cable. Then plug the wired FM modulator into the antenna connection on the radio, and the antenna cable into the FM modulator. If the FM modulator has a frequency selector, choose the frequency with the least interference in your area. Some cars (such as GM and Nissan models starting in the late 1980s and plenty of others in the 21st century) use oddball proprietary antenna connectors on factory radios instead of the typical Motorola connector. If this is the case with your car, you may need to buy an antenna connector adaptor.

Find power:
Use a voltmeter or circuit tester to look for a wire that has juice when the ignition switch is in the on or accessory position, and is dead when the key is switched off. The radio circuit is your best bet. Here again, your car’s service manual or the Internet will help a lot.

Connect power:
Using splice connectors, attach the wire from the power switch that came with the FM modulator to the power source you located in the previous step. If the modulator does not have an inline fuse, we recommend adding one to the positive wire. Connect the ground wire from the FM modulator to a good ground connection under the dash. Mount the FM modulator’s power switch in a convenient location, near the radio or centre console.

Tidying up:
Plug the RCA connectors of the audio input cable into the FM modulator. Route the end with the 3,5 mm plug to a location inside the glove box, centre console or other easily accessed but hidden location. Secure the FM modulator under the dash with zip ties. Gather the loose wires with additional zip ties. Don’t make it too tight – you don’t want to crimp any wires.

Test the audio:
Turn the ignition on, power up the FM modulator and connect an audio device to the 3,5 mm plug; tune the radio to the FM modulator’s frequency and make sure you’re getting a good audio signal.

Add Bluetooth:
Remove your test connection. Charge your Bluetooth adaptor and pair it with your smartphone, tablet or MP3 player. Connect the 3,5 mm plug to the Bluetooth adaptor. You should be able to feed audio through your radio with Bluetooth now.

Bonus step:
If you want to get fancy, hardwire a USB car charger into the same power source you used in “Connect power” and keep the Bluetooth adaptor plugged in at all times. This will require disassembling a USB car charger and soldering wires to the charger’s power circuit. If you’re not up for that, keep a charger in the car and recharge the Bluetooth adaptor when needed – that’s what we did.

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