We picked up our R52 earlier this month and one thing I knew I would want to do was double-check the work of the aftermarket radio installation that was performed at Best Buy some years ago (under the previous car's owner). The tip-off to me was that there was an aftermarket antenna attached to the inside of the windshield...if the installation had been done properly, that shouldn't have been needed as the factory antenna/antenna-amplifier could have been used.


So, I take the dash apart, remove the radio and find...this. Wiring nuts do not belong on a vehicle accessory installation. And there is no sign of the proper interface to connect to the factory Harman Kardon amplifier.

Here's another view of all the wiring that was in the dash just for the aftermarket radio. Way too much extra length left on the wires. On the plus side, they didn't just cut off the factory radio connector, and they used an adapter...but this car needs an intelligent adapter to work with the factory Harman Kardon amp and speakers, and they didn't use that.

The factory HK amp sits underneath the passenger seat...or at least, it should. The previous owner mentioned that Best Buy did the aftermarket radio installation...and it shows. The first aftermarket radio that was installed was a single-DIN flip-up Pioneer AVIC unit - which is a really nice radio, but requires a lot of additional boxes. I've seen/fixed a number of BBY installations, and my read of their work is that their main concern is finishing the install quickly (time = money, right). In this case, they didn't figure out how to keep the factory amplifier working, so they yanked it out and used the space to fit the extra boxes needed for the Pioneer AVIC. What a mess...

After all the unnecessary boxes were removed (there is a simpler Pioneer headunit in the car now that doesn't use all those extra modules), here is what I found for the BBY amplifier by-pass work. At least the factory amplifier connector was still there, but the speaker wiring connections were all hacked up as they tried to make some sort of connection from the radio to the speakers while by-passing the factory amplifier connection.

After a lot of solder and heatshrink, all the factory amplifier wiring connections were restored.

I keep some soft-wrap tape on hand for repairs like this...it matches the style used on the factory wiring loom.

Until I find and install a factory amplifier, I created leads to interconnect the speaker outputs of the radio to some of the factory speakers. Not all 4 channels route through the factory wiring loom to the amplifier. The factory radio sends a left and right channel to the amp, and then bus communication messages handle the fader, balance, etc. right from the amplifier. At least the factory connector and wiring is left in tact, this way

This is the wiring adapter for the AX-BM9112 adapter to be used with the factory Harman Kardon amplifier. It's all wired up to the Pioneer's radio connector harness.

There were a couple of wires to clean up at the radio connector, too.

I also re-located the handsfree microphone. This position puts it closer to the driver and hides the wiring better, as the original location had it clipped to the headliner trim right against the windshield.

Here is the dash, ready for the correct adapter to be attached and the have the radio reinstalled. I also used the Metra 99-9302 mounting adapter plate, which was left out of the previous installation work. The Pioneer radio sits firmly in the dash, now.

Here is the radio back in the dash (sorry for the dark picture). At least I can sleep better knowing what the real situation is with the wiring behind it, now! I do still have to sort out why the ASWC-1 is not powering up, though, so that I can get the factory steering wheel controls working.

So the remaining issue I need to sort out is why the ASWC-1 isn't powering up and recognizing the factory steering wheel controls. The ASWC-1's power-on LED does not turn on with ignition, which is weird. I've installed a number of these ASWC-1's before, so I am familiar with them. But this one is supposed to work in conjunction with the AX-BM9112 adapter and be more straightforward, with no additional programming required. The only extra lead off of the ASWC-1 harness in the AX-BM9112 setup is labeled -ACC, but I believe that is a switched output, and not a seperate switched power input to the ASWC-1.

I wanted to add, for my temporary amplifier by-pass connections to get the Front Left and Front Right speaker channels working (again, a temporary solution until I get a replacement R52 HK amplifier), I went with:
Pin 38 to pins 33 and 11
Pin 30 to pins 34 and 12

Pin 9 to pins 31 and 13
Pin 17 to pins 32 and 21

 

Well, duh, found my own answer on the ASWC-1. From the AX-BM9112 instructions, in the "Connections to be Made" and "From the aftermarket radio to the AM-BM9112 harness" section:
"Connect the RED wire to the accessory wire. NOTE: There will also be a RED accessory wire on the 12-pin pre-wired ASWC-1 harness to connect as well."

So, I'll go back in and correct/connect that lead, and see how things go from there.

 

Just an update...I did get the steering wheel controls working, once I connected that RED wire on the ASWC-1 harness.

And, I ordered a used R52 Harman Kardon amp to finish the stereo repair. It arrived today and my daughter helped me install it - the audio sounds MUCH better, now

 

Congrats… and not all of us were hacks like that. Liked your relocated mic location and going to stealborrow it when we eventually do the Bluetooth aux in my son’s.

 

Present company excluded on the "hacks" inference, of course

Thanks for complimenting the microphone position. I was a Program Manager at Motorola for their pro-install Bluetooth carkits back in the day (depending on when you were at BBY, you may have put in an IHF1000 or T605 carkit at some point?), and I have installed hundreds of those over the years. Keeping the microphone away from potential noise sources was always the key for best uplink audio quality, so I would try to get them in the middle of the front of the roof somehow, usually by the overhead console assembly. I never liked positioning the mic on the A-pillar (wind noise potential from a cracked or open window, as well as from the wind rushing at that point of the windshield/roof) or top of the steering column (nice direct path to the driver's mouth, but the potential for coupled noise from the hollowness of most of those trim pieces) - but I saw a lot of them installed that way.

If you're interested, I just wrapped up a full stereo system upgrade on my 350Z - details are here: https://my350z.com/forum/audio-build...san-audio.html

 

Always am and very clean work. Like hidden systems much more than look at me show car ones. Been a quarter century now since I worked for them so this would have been long after my time there.
Just finished tuning my match up7bmw in the f31 myself Had about 20 hours in the initial tune, and then 6 months listening before I spent 4 hours making some final tweaks to it. There may be a few slight improvements still to be had in terms of t/a imo but I need to live with it a while first to make sure my ears/mind aren’t deceiving me with change is better (but it’s worse).
besides I have fun to be had on r53 now.