Headunit Replacement Thread

Update time!

Got the pins out pretty easily using a pin removal tool. And installed them in pin positions 22 & 11 (voltage detect & ground).





I found that the HFL module uses a standard JAE 28 pin header / socket housing pair. Honda loves using JAE connectors it seems. They were also used extensively in my OEM stereo from my previous Honda.
I'll need to check the pin pitch and overall width before i order them, however.


I can buy one of these for like $2 from Mouser (which is local to me here in DFW).
I plan to cut the header pins just short of the 90 degree bend and solder the wires i need directly to the pins. Then heatshrink over them.
That's the controls and mic handled.

Originally, i was going to just run the USB extender (included with the radio) to the stock location.
However, upon researching that, there is no direct connection between the USB port and the radio on my CR-Z.
It is done through a little "USB Adapter Controller" box, located inside the dash (under the radio, right side).
On the nav-equipped CR-Z's, the USB comes straight to the headunit, and there is an "FM Distributor" in place of the "USB Adapter Controller".
The pinout suggests it's only job is reading USB audio (USB 2.0 only lol) and controlling USB device operation.

I think i'll just remove the entire module and adapter together. I'll run my USB extender down through the stock location.
*there is a much better idea wherein you just keep the stock USB wiring but get an adapter to convert the 5-pin connector to the aftermarket headunit (thanks MarioSilva)
Seeing as how the Alpine stereo only has USB 2.0, that is a much better solution.

Mouser got the connectors to me in literal hours (for $5 after shipping even).
One of them had the aformentioned 90 degree headers for mounting to a PCB.
The other, quite surprisingly, had no bend:



The part number is: 656-MX34028UF2 (Mouser) or MX34028UF2 (JAE).
This makes it a bit easier.
Before i soldered it together, just to be safe, i went out to the car and made sure it would plug in.



And they sure did, like butter!
I estimate i'll need about 2 feet of wire to reach the connector from the stereo harness.

I ordered a Scosche TAUSB01B which isn't listed as working with a Honda but one review stated it worked on their 2016 CR-Z.
It will be arriving here tomorrow morning (again really fast shipping) but it was $14.

All done! (But i ran into a few issues)


From experience, i wanted to make sure the radio powered up and everything worked before i continued with installation. Interestingly, the clock appeared on the gauge display:

And clock options appeared on the menu options, whereas before there was no option for clock adjustment. (or maybe i just didn't see it???)

All working, so let's continue to install:


My wiring for the HFL plug was just barely long enough to reach. I zip-tied it up out of the way of the cabin air filter:



I did as MrFastFox666 advised, and just zip-tied the USB to the panel here (as strain relief):



The handbrake wiring was pretty simple, a little plastic cage covering the crimp connector. I removed it and soldered my wire to the crimp connection (easier than crimping new connection). And reinstalled the plastic over top:



Sadly, i broke the little blue tab (trying to position the wire in a better spot). I put zip ties in to hold it until i can buy a new one.

You can disable the clock using the steering wheel controls (like you would change lighting settings):


I spent several hours today trying to figure out why the microphone was not working.
I went over circuit diagrams and thoroughly tested everything i could find.
Still not working, however.

I bought a new 3.5mm cable with lower gauge wiring + shielded to match what was already there.
Here are the three ways i attempted to wire up the stock mic to work with the Alpine HU:


I tried C first, using the microphone supplied with the Alpine HU. But it was not shielded. This one resulted in a really bad mic signal.
I tried B next, hoping that the Alpine HU could receive a balanced signal. But it couldn't. This one resulted in no mic signal whatsoever. (no ground signal connected with that wiring)
I tried A last, thinking this is like XLR balanced to unbalanced wiring. This one had the best result but it's still incredibly quiet.

Next i checked the impedance.
The stock Alpine HU mic was 2.2kΩ.
The stock Honda mic is 7.5kΩ.
I am thinking this is the primary reason I can't get any good signal from the mic. I think the HFL unit has a higher gain pre-amp built in for the microphone.
I turned the mic volume all the way up on the HU and it is still almost imperceptible.
Also It really should mix the shield and - signal at the end of it's travel (near the HU) rather than halfway through.

I then pulled the mic out of the HFL / dome light fixture: (sadly i broke the tiny wires from the mic to the plug)



I am thinking i'll just put a lower impedance microphone in and plug it in to that little socket and voila.
Any suggestions? Something i'm missing?

Update: upon taking apart the stock mic, i see some passive circuit components in it. Likely a band pass filter.

And the mic only has two connectors (the outside metal is just hooked up to the bottom connector)


I ordered the original Alpine microphone and i'll just cut it up and install it inside.

Another small update:
Probably won't be able to work on the car this weekend as Texas has decided to go full winter wonderland.



I did get the new microphone (it was listed as original Alpine, but it's clearly different than the one that came with the radio).
Or maybe Alpine sources different manufacturers for their microphones...

Anyways i took it apart very carefully and ran the cable through the little stock rubber isolator.
The diameter is the exact same as the stock microphone. But the impedance is correct for what i need.

The only thing i need to do is terminate it with the white plastic connector and it should just work. We'll see.