It was time for me to do something about the stereo in my 2001 SLK320. The factory Becker gave me uneven FM reception at best, and to my ear it sounded just plain lousy. Most stores won't even touch these cars, but doing a DIY head swap is actually pretty easy. I don't describe the whole process here, but I do include all the pieces of the puzzle by giving helpful links.
I went to the Crutchfield website (you can guess the url) and picked out an Alpine CDE-9845 for only $159. It's last year's model, so it's on sale. This unit had everything I needed: auxiliary input jack on the back, a pair of line-outs, and the ability to turn off the PA amp when using line-outs. It also comes with FREE connecting adapters for both the wiring and antenna! Radio removal tools are also in the package. Free shipping, too...
Here's the trick: According to Crutchfield's website, there is no data available for the 2001 SLK. So I lied and said it was a 1998 Mercedes C-Class
without Bose. This little ruse got me the right wiring harness connector and antenna adapter.
Next, I downloaded the excellent instructions from slk32.com (
http://www.slk32.com/pages/radioupgr...ioinstall.html). These instructions describe the process in great detail.
However, there are a few changes to this procedure that I'd like to note. For starters, I did not need to cut the wiring adapter in half -- it fit perfectly. About the only difference I noticed between the chart for the wiring adapter and actual wiring of the head unit is that the 12V (always on) and 12V (switched) lines are reversed. Crutchfield also makes note of this when you buy the head unit. Everything else seemed to match. I'd suggest checking the wiring yourself anyway.
Here's a link showing the stock head unit wiring:
http://www.beckerautosound.com/1492.html
Also, I used the LINE OUTS and not the speaker outputs -- these feed into the Bose amp, which I kept (for now). I also soldered all connections and used shrink wrap (hey, I'm an electronics geek).
Once everything was wired up, I noticed that I was getting sharp pops every time I changed stations or settings. From a previous thread, I learned that a "ground loop isolator" from Radio Shack (part no. 270-054) installed in the LINE OUT wires got rid of the problem. Easy fix.
In order to stuff all the spaghetti at the rear of the radio into the area behind the dash, I removed the kick panel next to the console on the passenger side. To do this, I unscrewed 2 screws that hold the panel under the glove compartment and pulled out that panel. Then I unscrewed the plastic screw holding the footwell vent, pulled out the vent, and removed the screw holding the panel in place. It takes a little creative tugging to get the panel out, but it can be done. Then I could easily see into the area behind the head unit.
Finally, I used some foam rubber to help keep all the bits from rattling around back there. You could also use tie wraps to hold stuff down, but this method could be a little awkward.
How does it sound? Fantastic!!! The whole thing took me a couple of hours, and it was really worth it...
Linear Mode
