The Yellow Wire and the New Car Stereo

Fig A: Old car stereo. 


Our old car stereo was practically a dinosaur.  See the cassette deck there?  Some of you probably don't even know what a cassette tape is.  It has only been bearable for all these years because we got a plug-in Belkin ipod tuner thingo, that sent the ipod songs into the radio of the stereo unit.  This kept us mostly happy for quite a long time (Fixit's complaints about the alleged crap on my ipod notwithstanding), but then the plug that we used to connect the ipod to the car deteriorated.  When we bought it, you just squeezed the sides and pulled; within a year we started to have to poke a key in the sides to remove the ipod.  Eventually it took 5 minutes jiggling the key to remove the ipod, which we could have dealt with, had the exposed wiring not meant that the radio signal started dropping out every 90 seconds or so, which meant I had to drive one-handed in an effort to keep it in a good position if we wanted any music.  Quite infuriating.

So I went to Aldi and grabbed the $80 stereo special.  Then Fixit tackled installation.  Due to confusion about the wiring, this is how my car looked in the interim fortnight.

Fig B: There's a hole in your dashboard, dear Stomper dear Stomper


We tried googling stereo wiring diagrams (we would have been fine if we lived in the US, but nobody posts diagrams for Australian Corollas.)  I even tried emailing the Toyota place we used to get the car serviced, but that was a waste of typing, they still haven't replied.  Then I asked our local mechanic and he said you don't need a diagram really and to ring him if we needed something explained.

So Fixit got as far as he could logically deduce, welding wires together or something, but the stereo still didn't work and he was starting to assert the unit was faulty and question the wisdom of buying electronic equipment from supermarkets. At which stage I got him to show me what he'd done, asked a few questions and then said it must be that yellow wire, what happens if you connect the yellow wire to the car?  Because the yellow wire clearly came out of an important hole/socket and yet it was dangling idly. Anyway, what happens, my friends, when you connect the yellow wire, is that the stereo works.
Edited to add: the yellow wire is the Constant 12 Volt Supply. It is used to keep constant power to your stereo so that the memory doesn't lose data such as radio presets and clock time. It has a fuse as a safeguard against stereo malfunctions that could cause fire.
Fig C: Whizzy new stereo.


Unfortunately my technical savvy did not extend to realising the difference between a stereo that is mp3 compatible and one that likes ipods. Live and learn. Ipods, as I sort of knew, play mp4s. The new stereo rejects those mp4s and therefore my ipod, and now I have to figure out if I can be bothered converting all my mp4 files into mp3s and sticking them on a usb stick.  It sounds like a big job.  On the other hand, a cd only has 11 songs and that gets boring quite quickly.  My ipod, on the other hand, has well over a thousand songs and provided you are not Mister Fixit, is endlessly entertaining.