Miata Mods and Updates – One

The Miata came with a factory radio that had a six disk CD changer built into it.

Factory radio.

Unfortunately it had two issues:

  1. There was no AUX in or Bluetooth.
  2. The CD player would only load one CD and then was reluctant to return it.

So I decided to do something about it. I did a little research and discovered that there is an adapter that you can buy that will add Bluetooth to the factory radio. It fakes it out by pretending to be a CD player – kind of like the adapter in my BMW did. It costs $135.

I also discovered that unlike the 2005 Subaru, the climate controls are not linked to the factory stereo and there are replacement dash inserts that will hold single or double-DIN radios! Yay!

Then I went to Crutchfield to see what radios with Bluetooth cost and found out you can get a reasonable JVC unit with Bluetooth, AUX in, USB in, and a CD player for about $90. Add on the dash insert, the wiring harness and an adapter so the steering wheel controls still work and the cost is about $140. SOLD!

Last Friday night I soldered up the wiring harness. It’s pretty much “match the colors and make it neat” until you get to the steering wheel adapter. Surprisingly that only takes three wires. One to the radio, one to the car and one to ground. It must use a serial protocol or something, and it must be somewhat standard.

The adapter is a microcontroller of some sort. It has a USB plug for updating the firmware if needed.

Starting to solder. On the left is the plug that goes into the new radio. On the right is the socket that you plug the car harness into.
All done, mostly neat. The black box is the steering wheel control adapter. The two bare wires need to be spliced into the car harness – the red socket doesn’t have the required pins for them (which is dumb.)

I also mounted the new stereo to the dash panel. It took about a minute.

DIN mounts are easy.

On Saturday morning I went out, disconnected the battery, and yanked the old radio out.

Hole in the dash. Old stereo in the footwell.

I had to cut two wires on the car harness and solder the new harness to it. I suppose I should have put a plug in, but I don’t expect anyone will be back in there again, and I did leave some stubs in case someone wants to put a factory unit back in.

After futzing around a bit to figure out where I was going to stuff the harness wires and adapter I came up with a plan. So I plugged in the harness, reconnected the battery and turned on the ignition. The lights blinked on the steering wheel control adapter box and the stereo turned on, so yay! I tuned in a station on the stereo and tried the volume button on the steering wheel. Nothing happened. Well pewp.

So I re-read the instructions and then read the troubleshooting section which said to turn on the ignition and then hold down the reset button for two seconds. Then you have to count the flashes to make sure it identifies the correct brand of radio.

So I did that, and it initialized itself again and then flashed to say it found a JVC radio. Okay. So then I tried the steering wheel buttons and it worked!

My theory is that the radio had not finished booting up (yes, it has to boot up – takes about 5 seconds) the first time that it scanned so it didn’t detect it properly.

The stereo also came with a mic you can mount to the A pillar, so I pulled off the A pillar cover and some more dash trim so I could run the wire for that.

Finally I stuffed all the wiring in and mounted up the dash insert and replaced all the trim panels and all that jazz and now I have Bluetooth for my car!

All done!

I haven’t tested the phone call operation yet, I need to call someone. And today I managed to un-stick the mic from the A pillar trim, so I need to remount that.

I have to say, the Bluetooth playback control for Android needs some work. According to the directions, if I had an iPhone I could navigate folders and the like, but with Android all I get is forward and reverse unless I tether the phone with a USB cable but that kind of defeats the purpose of having Bluetooth.

It is nice to be able to start the car and have my phone just pair up and start playing though.

In other update news, today I replaced the spark plugs and drained and refilled the power steering fluid.

The old plugs where probably not original (since they were labeled “FoMoCo” and not “NGK”,) but since the car has 99,500 miles on it I figured I’d just replace them anyway. It does seem to idle a little better now.

The power steering fluid was pretty dark. The Miata uses Dexron II ATF for the power steering so it should be red, but this was pretty black. Again, I have no idea if it’s ever been changed.