Help with new Head Unit for my W202

[RandyL]

Hello,
I need info on what's involved and wiring diagram for the stock unit in my 1996 C220. I believe my car is a W202 and has the factory Bose system (speakers on all 4 doors and small woofers on the rear deck).

Here are my concerns:
-- Can I easily hook up an aftermarket head unit to the existing system?
-- What's the procedure to remove the dash trim and radio?
-- Is there a special CODE I will need to know to install the new stereo?
-- Will the new head unit (common consumer brand) integrate OK to the Bose system without distortion and bad sound caused by incompatibility?
-- Where can I get a stereo wiring diagram for the car
-- I heard the VW wiring adapter can be used on the MB (part number?)
-- I bought one of those line/level adapters that say it will allow hookup to factory Bose systems...is this all I need?
-- Considering I have 4 door speakers and woofers on the rear, will the 4 speaker wires from the new stereo be all I need to hook up or will I need to hook up the woofers to the new unit's subwoofer RCA outputs? I'm thinking the Bose system will automatically cross over the system and route the bass to the woofers using its own internal circuitry.

Also, I have another 4 channel amp my wife bought me. I heard that the Bose speakers are 1-2 ohms each. I wonder if it would be better for me to simply remove the Bose amp (incedentally, what is the power rating on the Bose amp?) and speakers and install new speakers all the way around. Will I be able to use the factory wiring to prevent me from having to run new wires to all locations?

I do apologize for so many questions...but I want to make sure I have all the info I need before I do anything. I do my own installs on my other cars (Chevy & Dodge) but I'm not familiar with MB setups. Thanks!

[96C220]

Originally Posted by RandyL

Hello,
I need info on what's involved and wiring diagram for the stock unit in my 1996 C220. I believe my car is a W202 and has the factory Bose system (speakers on all 4 doors and small woofers on the rear deck).

Here are my concerns:
-- Can I easily hook up an aftermarket head unit to the existing system?
-- What's the procedure to remove the dash trim and radio?
-- Is there a special CODE I will need to know to install the new stereo?
-- Will the new head unit (common consumer brand) integrate OK to the Bose system without distortion and bad sound caused by incompatibility?
-- Where can I get a stereo wiring diagram for the car
-- I heard the VW wiring adapter can be used on the MB (part number?)
-- I bought one of those line/level adapters that say it will allow hookup to factory Bose systems...is this all I need?
-- Considering I have 4 door speakers and woofers on the rear, will the 4 speaker wires from the new stereo be all I need to hook up or will I need to hook up the woofers to the new unit's subwoofer RCA outputs? I'm thinking the Bose system will automatically cross over the system and route the bass to the woofers using its own internal circuitry.

Also, I have another 4 channel amp my wife bought me. I heard that the Bose speakers are 1-2 ohms each. I wonder if it would be better for me to simply remove the Bose amp (incedentally, what is the power rating on the Bose amp?) and speakers and install new speakers all the way around. Will I be able to use the factory wiring to prevent me from having to run new wires to all locations?

I do apologize for so many questions...but I want to make sure I have all the info I need before I do anything. I do my own installs on my other cars (Chevy & Dodge) but I'm not familiar with MB setups. Thanks!

Ok, first things first.

You need the vw adapter to not butcher the factory wiring.
Make sure you get the one for late 90's cars. To be safe ask for a 98 passat - I know that is the right one.
All you have to do is interchange constant and switched power, (from the harness to the head unit).

Now a 1996 bose setup uses a line level input setup. So you need to wire that line level converter between the speaker outs and the speaker wires on the VW harness.

Bose speakers are indeed 1 Ohm, I've never had any real luck powering them with aftermarket amps... you could theoretically add a power resistor in series, to make your aftermarket amp see a higher impedance load, but you will waste a bit of your power as heat being dissipated by the resistor.

Bose amp is like 20 watts per channel but don't forget thats into 1 ohm.

Power = Resistance x current^2
So comparing to a standard 4 ohm setup, thats 80 watts per channel nominal.

The sound especially with a CD will be VERY good for stock....

As far as the rear speakers, its all split by passive crossovers....
There are actually 4 woofers in the rear deck, the outboard ones (towards the edges of the car are part of the main speaker system (wired with a 2 way crossover to the rear door) the two inner "woofers" have a dedicated mono channel from the bose amp, and are essentially mini subs.

Since you already have the line out converter, wire it up this way, and see how you like the sound. You can always gut the whole thing and redo the rest later if you aren't satisfied. With my car, what I did was add an aftermarket head unit, to the bose setup, and then used the head's sub rca's to an amp in the trunk to run a 12" subwoofer.... Sounds very, very good.

You dont have direct wirng to every speaker in the car at the bose amp harness, but you do have lines to the front, rear, and rear deck inner woofers.

At some point downstream they split and there are passiver crossovers, so to redo the whole thing you need to rewire the car.

As far as removing the head unit... you need two special tools from the dealer.

check out my page on how to do it...

Radio removal link

Any additional questions, please free free to ask or e-mail me.

Take care,

George

geoandroulakis@optonline.net

[RandyL]

George,
Wow..thanks for the detailed info! If any other questions do pop up, I will be sure to contact you! I do like the stock sound of the bose system...it's just that stock head unit's LCD has bled and now can't read anything! I hear this is a common problem with these.

[96C220]

I have replacement units... both pre 99 ( The one you currently have) and the upgraded 99+ unit.

If you just want to go that route, let me know.

George

[RandyL]

I already have a Panasonic head unit I bought. thanks for the offer though. DO you know where I can get a schematic showing the color codes for the factory system?

[96C220]

I have the wiring diagram for the head unit, showing pin locations of all the wires.

I also have MY car's bose system wiring diagram but I think yours is a little bit different.

If you want either, e-mail me.

geoandroulakis@optonline.net

Take care,

George