Pimping out the geomobiles

A few days before we were going to leave on a week-long roadtrip, my spouse suggested we swap out her original radio for something that would play MP3s and, ideally, had an USB port.  I did some quick research and found a JVC unit that work fine.  The other requirement was maintaining compatibility with the steering wheel controls.  For most current radios, this involves buying an interface computer that’s patched between. Crutchfield set me up with the PAC unit.  (Spoiler alert: I have not been this frustrated with a product in quite a while.)

The order arrived (as expected) the day before we were going to leave for our trip.  While she was running some additional bonus last minute errands, I was soldering the vehicle-specific harness in anticipation of this being a quick job.  After she got home, I popped off the dashboard using Crutchfield’s excellent diagram and discovered … I’d been sent the wrong harness.  Merde.  Put the old radio back in and we vacationed.

When I returned, I had Crutchfield sent out the correct harness and I soldered its interface on.   Took the dash apart and popped the radio in.   Worked great.  Next, I was going to add the steering wheel control interface.  From there, I descended into madness.  Among the problems:

  1. The package includes a plastic bag with six resistors and a capacitor.   There is a vague reference to possibly needing the capacitor if the controls are intermittent.  I had several WTF moments until finally just assuming none of it was needed.
  2. Instructions are printed in a four point font.  The sheet lacked my vehicle, so I had to go to the web site where its computer generated configuration had confusing messages like:

    Connect pin 9 to ground if available.

    Jim’s thought: ‘If available?’  Does that mean optional?


    “Step A: The purple loop wire does not need to be cut. (unless stated different previously)”

    Jim’s thought: You mean you don’t know?!


    Note #9: No other notes needed, skip to the next STEP

    Jim’s thought: disregard this thought.  Do not pass Go.

  3. It requires splicing wires from the original harness.  The pin diagram is tiny and oriented from the pin side (versus the wire side, where you’re actually splicing).  They make no attempt to tell you what color wire you’ll need to splice.  There’s not a lot of room in the dash to be looking at wires.
  4. The unit requires Every.  Fracking.  Button.   Individually.   Programmed.   blink, LED, blink!

Installation attempt #1: unit wouldn’t program.  Reason (20/20 hindsight): I misread the “if available” instruction as being optional.  It isn’t.  The steering wheel buttons work by varying resistance.  If pin 9 isn’t grounded, it’s not going to send any voltage, as my voltmeter verified.

Installation attempt #2: Got to experience the joys of programming Every.  Individual.  Button.  The switch on the side of the box requires a different setting for the radio (JVC = #2) than programming the car buttons (#3).   The instruction sheet omitted mentioning this transition.   When I re-read the sheet, the unit got confused and wouldn’t respond at all.

Installation attempt #3: Got everything connected correctly and working.  Bolted the dash up, and… volume up was intermittent, volume down didn’t work.  In retrospect, this may have been indicative of needing to solder that capacitor across the spliced pins.  I took the whole thing apart and ran a voltmeter on every connection.  Just to be sure, I resoldered them all and reprogrammed the box from scratch.  Only this time, it wouldn’t respond at all.  I was really busy with work the next week and hoped my spouse would forget about it.  She didn’t.

Installation attempt #4: I threw the PAC device away and installed Metra Axxess ASWC unit.  This was nearly opposite in experience: the had instructions for my vehicle, showed what color wires to splice (which I’d already done), and no programming: the box just figured out what it needed and everything worked fine.

Total time spent on this whole endeavor: 6 hours.  I can now take my minivan dash apart with my eyes closed.   (Seriously, that’s what I did on #4 – a useful life skill if I ever want to go into the business of removing Mazda MPV radios.)  I can now swear in at least two languages.


When not cursing the steering wheel interface box, I taking an interest in upgrading my car’s radio (to have bluetooth for playing Pandora and audio books) and speakers.  My car’s only ten years old — and lacks steering wheel controls — so this would be a fun little project.   I used the model my spouse’s radio replaced as it had the same basic functionality, but was $50 less.  For speakers, Crutchfield’s configuration tool offered only one choice for front-door speakers (because there is not much depth between the frame and window).  Worse, the speakers they recommended were equivalent to what I spent on everything else.

Professor Bing found a Subaru enthusiast forum whose members have documented similar work to their vehicles.   The most useful takeaway was a link to an aftermarket flange that would let me use cheaper, better, cheaper, standard, cheaper speakers.  The flange is a delightfully simple.  The three original speaker screws are used to attach the flange to the door.  The new speakers come with new screws and bolt onto this.  The gap is enough to separate the (deeper) speaker from the glass.

Oh my, was this easy to use.

The speakers lacked plugs.  No problem, I just snipped off the one from door, soldered wires, and used wire screws just in case I got the polarity wrong.

I really felt I should fill the door with styrofoam shipping peanuts.  Poor man’s soundproofing?

After a quick test, I put the speaker and the door back together.   This speaker is twice as deep as the factory version.

Party Rock Anthem in … 3… 2…

Total time to replace the radio and speakers, including soldering, was under two hours.   The really cool part is it’s a lot more convenient to listen to audio books on the way to work.  I’m currently 2/3 the way through The Emperor of All Maladies.

The next project is to do some holiday lighting.  (Okay, not really… )

2 thoughts on “Pimping out the geomobiles”

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  2. I love this post. I had a better experience with my own car radio upgrade, but I didn’t have steering wheel controls to mess around with (thank goodness!), as in your second story. Nice work with the speakers! 🙂

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