Stereo and Keyless entry upgrades.
This 500E arrived with a Pioneer DEH-P9300 in-dash CD. While a nice unit, it did not play MP3's, only audio CD's. Attached to it was a 12 disk Pioneer CD changer as well. This was a fairly high end deck a few years back and the sound quality and feature set was very rich.
For my replacement, I chose to stay with Pioneer, mainly since this particular brand is one of the few still making Mosfet high power head units. The DEH-P8MP Premier has a internal Mosfet 60 internal amp (versus the 50 watt Mosfet amplifier of the DEH-P9300) although this head unit does not have some of the sound shaping functionality of the previous deck, the sound quality is very good. The additional power is put to good use powering the front 4" dash speakers and the rear 5.25" speakers. The door speakers are powered by a small ADS amplifier.
Next on the agenda was the addition of some low end. I did experiment a bit with Bandpass and some sealed box designs, but they consumed to much trunk space and required additional amplification and space. Although all these designs provided ample bass, much of which does get into the passenger cabin very well without the need for rear deck venting. This time around, I stepped up to the Basslink T. A single 10" sub mounted between two passive radiators and a internal 250watt amplifier. The length is about 40", which is ideal for the length of the 500E trunk. This picture shows a test fitting before I mount it.
To start, I
needed to remove the trunk carpet, spare wheel and accessories. Mainly, I
wanted to clean this area up and ensure I don't drill into my spare tire!
While the Basslink was in the trunk, I marked the location of the feet so I could drill the necessary holes for mounting. The passenger side mount sat on top of the plastic spare wheel cover, which is not a big deal.
Not I am ready to put everything back into the trunk and continue with the install. With the passenger side Basslink mount secured to this cover, access to the spare tire is not possible, but by removing these three screws, I can lift the cover up enough to slide it out without disturbing the Basslink.
I did not want to rely on just the mounting feet to secure the Basslink in the trunk. Plus, if I unbolt the passenger side mounting foot (to get at the spare tire) I wanted to make sure the Basslink did not become unstable. So I used some back strapping material mounted to the top of the Basslink and secured to the underside of the rear deck. Normally silver, I painted this back strapping material flat black to better blend with the interior. You can also see the signal/power cable that rises up and drops behind the trim panel.
And the finished product! I sacrificed less than 7" of the trunk depth and only a minor inconvenience when accessing the spare tire. The power/ground were routed behind the trim panels over to the battery where they were wired directly to the battery. I used a JL Audio install kit which includes 8 gage power/ground and a fuse at the +12 terminal of the battery. As always, Infinity makes a quality product that is clean and tight sounding.
The Basslink T includes a remote volume control that connects to the internal amplifier via a standard RJ-11 phone cable. I routed this cable along the drivers side of the vehicle up into the light switch area of the dash.
This is the Basslink volume control in its self contained box. Of
course, mounting this under the dash was not going to provide the best
appearance, so I elected to take the volume control apart and flush it into the
headlight trim panel.
Using the trusty Dremel again, a hole large enough for the volume control shaft was drilled and the nut and lock washer was installed prior to installing the volume knob.
The finished product. A nice OEM look which provides easy access while driving the vehicle.
Keyless Entry install
This keyless entry system is also a full featured alarm that comes with flip-key remotes very similar to the late 90's Mercedes remotes. Of course, this alarm did not have key blanks for Mercedes, but then again, you wouldn't want to use the supplied ones anyway, since they are brass. These are readily available from Ebay for around $40 or so.
Some more of the alarm accessories. The instruction manual was a joke though, poorly translated and barely understandable, lucky for me I have installed hundreds of security systems.
Under the passenger side of the rear seat lies the vacuum motor for the door locks. This is where the majority of the work is going to take place. Although not 100% accurate and written for a specific model of keyless entry, I referenced this instructions, http://www.mercedesshop.com/Wikka/W124Keyless between these instructions and mine, I believe just about anyone should be able to complete this installation.
Instructions for removing the covers and vacuum lines are covered in the other instructions so I won't duplicate them here.
Here are the two plugs we need to access. The three wire plug contains the ground, +12 and switched +12. I chose to use the green wire from the round plug, the green is from the passenger door, blue the drivers and yellow the trunk. Any of these three will work. Later model W124's have six wires here, two of each color, but only one of each color is the correct wire to use. Consult the other install guide for directions on locating that wire.
The alarm I chose does have on-board relays and includes several different ways to wire them for different types of door locks, but they don't include the single wire +12/-12 lock/unlock method that Mercedes employs. So I set the alarm to just emit a -12 lock and a -12 on unlock, then I used two outboard SPDT relays wired up as per this diagram. At rest, the door ckt operates normally, when energized, the ckt is broken and either a +12 or -12 is sent to the vacuum motor. Of course, what the other site does not tell you is that there is no way to initiate a arm/disarm of your factory alarm from this location.
If you need this system to arm/disarm your factory security system, you need to run your -12 trigger wires from your alarm up to the factory alarm brain location. Now keep in mind that your wires/colors may vary, just use my information as a guide and remember to always test your wires to ensure they are the correct ones. Connector 2 (small one) on the alarm brain is the where we find the wires. If you unplug it like this.
Your going to need the wire located in Pin number 6 (yellow w/blue stripe) to arm the alarm. You need Pin 7 (green with yellow stripe) to disarm the alarm. At rest these wires are +12, to arm, pin 6 goes to -12. To disarm, pin 7 goes to -12.
This is the relay diagram I came up with for the arm/disarm of the alarm. You need one relay for arm and one for disarm. NOTE, I realized a mistake AFTER I took the picture, 87a should go to the door lock harness and 30 should be the alarm brain. Please remember this if you use this relay diagram.
Here are my arm/disarm wires spliced into my alarm brain. When finished, everything tucks away nicely.
So, getting back to the flip key remote. The next step was to cut down my OE steel key so it would fit the flip key remote. This process requires a Dremel, some cutting wheels, grinding wheels and some small files to get the job done.
You need the original flip key blank to use as a guide, so you need to remove two small screws that hold it into the remote, don't loose the screws when you take them out, they are very small.
Basically, you need to make your original key look like the key you removed from the remote. Notice the tab end of the key, you want to duplicate this on your key using the tools mentioned above. You need to be very precise, otherwise it will not fit/work correctly.
Keep working your key until it fits perfect and you can put the retainer screws back in. Also test the opening/closing of the key, it needs to be centered correctly.
Here are additional instructions in Japanese to do the flip key modification
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