After cutting some plastic away, I was able to fit a wireless CarPlay/Android Auto receiver in the space originally occupied by the factory navigation LCD in my 2004 Mazda RX-8. It's a tight fit, so several right-angle extension cables are on order. While I waited for them to arrive, I thought I would hook up all of the original components. There were two reasons for this. First, because this replacement would make the original system inaccessible (can't interact without a screen) I wanted to wipe all personal data. Information like travel history, bookmarks, and so forth. Second, in case the new system doesn't start up as expected, I wanted to know I didn't break anything getting to this point. That turned out to be a very good call.

After I put everything back together, I turned the key to "ACC" (accessory) and while the dashboard lit up as expected, the center console did not. Usually, the LED status bar above the radio would display "mazda RX-8" in the center between the clock and thermometer, but that entire status bar stayed dark. NO text, no clock, no thermometer. Furthermore, the navigation hood is supposed to flip open to expose the display, where I can watch the old navigation system boot up. The hood did not flip up, and the screen stayed dark.

After taking a deep breath, I started on a list of diagnostic steps:

  • Unplugged and reseated all connections didn't help.

  • Checked the fuse box, the ACC fuse looked fine and has electrical continuity.

  • Turn everything off and back on: disconnected the battery, waited half an hour, plug it back in. Didn't help.

I removed the audio head unit for closer inspection on the workbench. While looking around for obvious signs of damage, I found the culprit:

This is one of four fastener positions holding the glossy black plastic audio control panel to the metal equipment cage behind it. For this fastener, I can see the serrated edge of a heat-set insert. I'm not supposed to see that! Apparently, when I removed this module, I pulled too hard trying to free it from plastic clips and ripped this fastener out.

Just inside the ripped-out insert was a connector like the ones I saw in the Toyota and Honda units I've explored. This is probably a standardized durable part that works very well for this application, but they definitely won't work when the two parts were held a centimeter apart by a stripped-out heat-set insert.

Now that I see the problem, it was easy enough to fix with my soldering iron.

And ta-da! It's back in. Reinstalling the control panel, I can see the connectors are now actually connecting. This time when I turned the key, I saw the LED status bar light up alongside working audio and HVAC controls. However, the navigation hood motor didn't move, and the LCD stayed dark. One problem down, but I still have more debugging to do.