Testing a car stereo

I have been cleaning up over the last few days and among the stuff I found this car stereo in my collection. Now my brother has some issues with the stereo in his car so I figured that seeing as I don't have an immediate use for this one I could probably pass it on if it worked. Follow on after the break to see how I tested this head unit to see if it was worth using.

This was where it got interesting as I don't have the harness that's needed to connect this unit to the car.

This was all I had to work with. Thankfully I managed to find a website that has the actual pinout of this connector in the back rather than just what wire does what; which normally would be very helpful but unfortunately not here.

One of the fist things I did was to open it up and give it a quick sniff and look for anything obviously burnt out. I did manage to connect this to my car using a Kenwood cable that fitted. But going by the blown fuse it wasn't wired right. Thankfully there weren't any burnt traces or components so it should be ok.

Using the pinout from pinoutguide linked above I managed to connect my bench supply to the battery +ve, battery -ve and ignition pins. I need to connect to the ignition pin otherwise all I can do is remember the radio presets and not actually turn it on. Thanks to my somewhat large and oversized alligator clips I actually connected both the ignition and the illumination pins. This is ok, as the illumination pin just lets the radio know how bright the dash is so it doesn't blind the driver.

Plugged it in and.. it works. Now at this point you can't try and play something as there are no speakers connected and that can blow final drive transformers. Probably not a big deal with a smaller unit like this, but still a good habit to get into I think. Besides this unit and many other basic audio devices use a single chip that does all the audio heavy lifting. If that was damaged I would probably either be able to see it, smell it or the device wouldn't function in any sensible form.

Over the next few weeks we'll probably do a quick post on how we install stereos or head units into cars. But until then now you know how to test a head unit that's been sitting in the back of your cupboard for a few years and you don't want to spend anything on if it's cactus.

Cheers,
Rex