Got my full set of brand new fuses through the mail today...Figured I'd wait and do this before tapping into anything else as the original fuses were close to falling apart.

...but still no power at the ignition wire
What the heck could be the problem? The original radio was working fine!

I'm almost there!

 

Hmm, you should be able to locate an ignition wire from the A/C panel or dome light wires. I don't really know what could be the problem. You need a wiring diagram and you should be able to source out the problem.

 

Would bridging it with the constant +12V drain the battery if I made sure to turn off the radio before I left the car? (for a temporary solution)

 

There's another remote cable around there...get your multimeter and test....maybe that's why i posted it was gray a long time ago....

 

Ah you know what I found! Attached to the cigarette lighter there was a cable and it provided ignition only +12V.

Perfect!

Now that I got power I can start trying to get the speakers to work hopefully.

 

Was it gray???.... lmao...just wondering... To me it's just easier to run a small amp in the back and power the rear speakers off that amp. You can use the head unit to power the front speakers.

 

I think that I will just use all 4 channels for now so not to spend any more money on an extra amp. I'm pretty content with the setup in my wagon so I'll do the same.

I'm trying to figure out which wires are for the front + rear speakers...Is there somewhere that shows how to do this? The DIY link earlier shows a fader...but all my wires are a different color.

I tried a few combinations, but didn't have any luck. I tested an old speaker lying around and it worked...so its just me having problems figuring out which wires are for which speakers.

Also same goes for the rear....Do the front speakers go to the fader along with the rears? I'm still not too clear on the wiring.

 

Got the front speakers working! There are a total of 4 connectors behind the HU (exluding the 4pin connector). Two of these connectors are hidden behind black insulation. These are the front speakers.

1/2 way there!

So all I need now is to find the rear speaker cables at the fader, correct?

Once I get this figured out and done, I'll do a write up so its super easy for anybody else who wants to do it for an early w124.

 

I'm still stuck on these rear speakers
I think I found the correct wires at the fader for the rear speakers, but I am lost on where the grounds are??

 

Got it!! I had the right wires, but the HU needed to be changed to push the fader back. Weird?

Either way I am very happy!

--------------

Here is a very and easy summary for anybody who searches so my 3-4 hours spent doing this could be done in 30mins tops (seriously)...

You DO NOT NEED to purchase an aftermarket $25-$30 wiring harness. This can be avoided....albeit a little more messy, but I wont be swapping the headunit ever again, so who cares?

This will work on 87 and earlier models I can tell you for sure....not sure about later years as I have searched, and some W124 models use different colored wires at the Fader...so this should clear up much confusion for the earlier models. This also "should" work for all NON-OEM-Amp setups with only a change in the fader's wire color. You can determine the new color by simple elimination. Just do all steps and skip the fader until the end then just cut it and do one-by-one while playing music til you find the right wire.

Disclaimer: Please remove negative cable from battery while doing this and ensure you have a fuse built into the headunit, or add in your own on the +12V constant wire.

Step1: Remove shifter + A/C wooden cluster then Cigarette Lighter. There is a DIY on this.

Step 2: Remove OEM Becker Unit. Remove power cord, Speakers L + R (2 channel), Chassis Ground and the Antenna.

Step 3: Cut the original Becker power harness off -- It will have 4 (four) wires. Wire them up with harness on new headunit.
OEM-Harness-Side:
Blue = Power Antenna
Brown = Ground
Red/White = Ignition +12V
Yellow/Black = Constant +12V
There is no illumination wire if your harness has one.
So match the names with the new harness. Pretty straight forward.

Step 4) Now head over the fader. Cut it off completely and pull out the following wires:
Black/yellow (+): power to left rear speaker
Black/white (+): power to right rear speaker
^ (Thank you to BodhiBenz1987 for the correct wires)
These are the only two wires you need. Tape up the exposed remaining wires for safety reasons.

Step 5) Run new wires from the Black/Yellow and the Black/White up to the headunit. Tape/Solder them to the positive wire for the respective speakers as shown above on the hew headunits wiring harness.

Now, behind the headunit, there are a total of 4 (four) little connectors as shown in the picture below:

Above you can see the male and female connectors. You only need the male one.

Front speakers: They were directly plugged into the 2 channel L + R in the beginning. Simply gut the male connector and attach the green to the positive (+) and the black to the negative (-) on the new headunits wiring harness. On the little male connector, it will have a L or R imprinted on it so you can tell. I would label each connector with tape for ease at a later date if anything comes loose or w/e.

Rear Speakers: There is NO grounds at the fader....instead, you should now have TWO remaining speaker male + female plugs left behind the headunit. Each of these will still have a L or R written on them. You are ONLY using the ground (black wire) from these. Wire the grounds to the new harness. Now, take your new extended positive (+) wires that you made from the fader, pull it behind the headunit and attach it to the positive (+) for each speaker wire at the new headunits wiring harness.

At this point the speakers should be working fine.

Step 6) Attach Chassis ground (my headunit had a bendable piece of metal that it attached to...Had to pry it up)

Step 7) Attach antenna

Step 8) Test if you have not already.

Might be a little confusing....but print it off and read it with yourself in front of the wires. Ask me if you have any other questions.

 

put a HU in a 92 300e today at work and it is much easier to just run all new wires to the front and the rear, and if you ever decide to take the HU out you can still use the factory harness, the only wires i spliced into from the factory harness was the ignition wire, constant 12v wire and the ground wire. There was still one wire connected to the 4 pin connector so i just kept it in there and pushed it to the back. When i cut into the harness I just gave myself enough room to re-solder the wires back together if it was someday necessary. Only took about 2 hours total and got some good practice cuz ill be doing this on my 420 very soon If anyone needs help with this just let me know.

 

Hello,
I'm currently trying to install an aftermarket radio in a 92 300E. the problem i'm having is my antenna doesnt look like any i've seen with the adapters. it doesnt have a single small nipple, it has several prongs. does anyone know where i can find an adapter for this? thank you

 

Ah, this is why I love good old Beirut. I went to a guy, paid 180$ for a generic medium quality Sony head unit, installation is free since I bought it from him.

Today, I sent 2 wires from the amp to the battery (positive and ground), and a wire from the radio to the amp. Then, I simply connected the sub to the amp.

So the end result is, I'm using Pioneer speakers (nothing fancy, medium quality stuff) connected to the amp/sub.

I really don't see what the problem is. There are more W124's than Beetles here in Lebanon, no exaggeration. Everyone knows how to work with them and I've never heard of anyone with a problem.

The only thing I can thing of is that your cars in the US are double dimm (if that is what it's called) and therefore might make it more complicated, but I don't think it should.

 

Recently acquired a 95 e320 sedan with original Bose head unit. I am thinking about replacing it with either a JVC KD-R900 Bluetooth receiver or a Blaupunkt Toronto 410 BT Bluetooth receiver.

Question 1:

If I go with the JVC KD-R900, would I need to rewire the speaker wires? My car doesn't have the infamous center console fader switch, and it has 2 factory amps on the right rear tire wall. I'm hoping it'll be a straight install if I can find all the needed wires from the back of the bose unit.

Any thoughts and/ or diagrams are much appreciated.

Question 2:

Will it be a straight connection with the new Blaupunkt unit? I mean would the wire harness from the Bose unit fit perfect into the new Blaupunkt unit?

Here's a link to the Blaupunkt unit: Blaupunkt: Bluetooth Tuner[view]=1353&no_cache=1&L=1


I want to equip this car with a decent bluetooth cellphone capability so I don't have to rely on those spotty Motorola bluetooth microphones.

Much obliged!

 

Previous owner of my 1994 E320 cut factory harness. I hooked up aftermarket stereo but cant find which wires are for front doir speakers. I have franticly searched just about every post related to stereo installation and can't find answeres to which wires I need to look for. Anyone know or can help by at least posting or emailing me pics of their wiring harness? Anything might help!