Where's the simplicity?

May 11, 2008 2:18 PM

Swapping a car's stereo head unit: I would really like to replace my car's ailing Blaupunkt CD player with a more modern head unit, ideally one with a front aux-in for my iPhone. Before I embarked on this I thought it would (should!) be as simple as popping out the old HU, slotting the new one in and simply reconnecting the connector block.

But it seems the process is rarely that simple. My car, a 96 Mazda 626, does not seem to have the pretty wiring harnesses to be seen in many online tutorials. It looks exactly like this.

A friend said that all aftermarket stereos connect to the car's wiring harness via an ISO connector so I presumed that as my stereo is almost certainly aftermarket the hard work was already done for me. But having bought the removal keys and had a look behind the stereo it doesn't look like it.

What are my options? I would dearly love to avoid soldering, splicing and dicing and have a nice clean solution involving adaptors or the straightforward swap I hoped for.

I guess if I buy another Blaupunkt then I can just swap head units? There are two connectors even though only the brown topmost can be seen in the picture. Do Blaupunkts continue to use this setup?

I've tried asking at the12volt and installdr, but without much success!

Any help appreciated!

posted by dance to technology (11 comments total)

Look into the availability of wiring harness kits for your car. It probably won't be as easy as unplugging your existing, and plugging in a new one, but probably not a whole lot harder. Crutchfield.com is a great place to start. Not the cheapest, but a great source of info
posted by Mr_Chips at 2:24 PM on May 11, 2008

It looks like the helpful previous owner might have cut-and-spiced the wiring harness, rather than paid the $10 for a harness with the right connectors. If that's the case, then buying one with the right connector won't help, because the connector will have been cut off your car's wiring harness.

Once in a while, it really is cheaper and easier to pay someone to do the work for you. The last time I replaced a car stereo definitely fit this. I figured, rather than pay the $75 the installer was charging, why not do it myself? But after I had to buy a wiring adapter, and then a couple bracket pieces, and something else, I saved all of $15... and spent a lot of hours saving that $15. And a long time ago I installed a stereo using the cut-and-splice method, and it worked fine, although it takes longer than just plugging in a connector, of course. So it's not really a big deal if you decide to go that route.

So -- make sure that doing it yourself really is the cheap way to go. My experience is that Crutchfield provides good instructions, and will get you pretty much any wiring connectors or brackets that you need. There are sometimes cheaper places, but not many with as good support for the incompetent DIY'er. But if it is a really weird set up back in your dash, and a local shop is offering free installations or deeply discounted stereo prices, then it might be really satisfying to let this be someone else's problem.
posted by Forktine at 3:04 PM on May 11, 2008

Are you sure the plugs on your car are not ISO connectors? Look at M-56 and M-57 on this page. The brown one visible on your photo is probably the speaker plug. The thick cable on the right in your photo goes to the radio antenna, this is also pretty standard.

Even if the cabling in your car is nonstandard, don't go cutting and splicing unless you're sure an appropriate adapter cannot be found, chances are the place you buy the stereo from will have one.
posted by ghost of a past number at 3:05 PM on May 11, 2008

Forktine writes "It looks like the helpful previous owner might have cut-and-spiced the wiring harness, rather than paid the $10 for a harness with the right connectors. If that's the case, then buying one with the right connector won't help, because the connector will have been cut off your car's wiring harness."

Yep, looks like some hack cut your factory connector off to save $10 by not buying the adaptor. They also appear to have used scotchlock connectors of the crappy chinese import variety rather than genuine 3m.

The correct way to install your new stereo is to first get a factory wiring harness from the auto wreckers and solder it up. Pretty easy because the harness colours will all match. Then you just buy the $10 adapter and solder it to your new head unit wiring harness. This is even easier because not only will the colour codes probably match but you can do it on the bench instead of in the car.

Also I'd recommend getting an iPod ready head unit. Instead of jacking in the front there is a cable that connects to the iPod's data jack and the back of the head unit. You can route this cable into your glove box or other convinent location (Miatas for example have a great little bin with door in the radio stack that works excellent for this purpose) and the head unit can control the iPod. Last one I did used a Alpine head unit that cost less than C$200 and came with the adaptor cable. The iPhone uses a different protocol than vanilla iPods so you want to make sure whatever head unit you buy is compatible if you go this route. All the Alpine units are and (at least according to JVC customer service) none of the JVC units will work (and I can confirm iPhone doesn't work with the unit in my dually).
posted by Mitheral at 3:51 PM on May 11, 2008

ghost of a past number - it looks like you're right - that that's what I have installed at the end of the bunch of wires. And the lone yellow wire going into the top of the radio? Is that constant 12v 'memory'? I wonder why it's alone...

Thanks everyone for all the help - really appreciate some sense being made of the situation.

So the absolute easiest would be to find a radio which uses this type of M-56/M-57 connection? Or is it possible to find adaptors which go from M-56/M-57 to an aftermarket radio?

I can't help but think the car radio wiring needs standardising some more!
posted by dance at 1:46 AM on May 12, 2008

Or - suddenly occurred to me - is perhaps the lone yellow wire a relic of an old hands free car kit? The car does have a Nokia external antenna installed...
posted by dance at 1:48 AM on May 12, 2008

If the yellow wire is connected to a prong that doesn't appear to be isolated from the chassis of the radio (IE: riveted to, screwed to, or part of the case or heat sink) it's a ground connection. Easy to verify in this case, just follow it to where it's connected to the body of the car.
posted by Mitheral at 8:31 AM on May 12, 2008

The last radio I installed had a wiring diagram stamped (or etched?) in the metal of the case. Clean off the dirt and look closely at all sides. Even if yours doesn't, check out the manufacturer's website, or call them, to see if you can get a manual for the old radio, which will give you the wiring diagram.
posted by Forktine at 9:04 AM on May 12, 2008

Mitheral, it doesn't really look like a grounding wire - there are a load of prongs for a female connector to fit onto but only one of the prongs has a wire going to it...
Forktine, I'll take a look and see if there's a wiring diagram on the case!
posted by dance at 10:14 AM on May 12, 2008

Is your radio antenna fixed or the kind that goes up when you turn on the radio? The yellow wire might be power for the motor that drives it.
posted by ghost of a past number at 11:16 AM on May 12, 2008

Based on this wiring diagram, I am pretty sure it's got something to do with the old hands-free system. Thanks a bunch for all the help, chaps! Here's hoping all this helps somebody else just starting out in the complicated world of car audio...
posted by dance at 11:51 AM on May 12, 2008