how to remove factory head unit

[alphanumeric]

well first off.... this is a whole stereo install topic.. on a 2000 c230k

I checked out the tweeters in my dash and the door speakers.. and it says they are 4ohms? I keep hearing they are 2ohms! wtf :confused:

anyways... I took out the map pocket under the head unit.. and unscrewed two screws so now that the whole center pulls forward..but! it does not come all teh way out.. whats the trick.. how does the HU come out?

I plan to install an Alpine unit with AI-net with teh Ipod controller.. with 1 amp for now to power a 10inch bazooka sub.. thx

[Denlasoul]

Originally posted by alphanumeric

I checked out the tweeters in my dash and the door speakers.. and it says they are 4ohms? I keep hearing they are 2ohms! wtf :confused:

anyways... I took out the map pocket under the head unit.. and unscrewed two screws so now that the whole center pulls forward..but! it does not come all teh way out.. whats the trick.. how does the HU come out?

First, if I am not mistaken, you can wire 4ohm speakers to have a 2ohm impedance.

As for the HU, you will need radio removal tools to get them out. See the two slots on the HU? The tools slide in there and "unlocks" the HU. Just pull it out from there.

[pnsji]

bose system = 2 ohm
non bose = 4 ohm

[c280steve]

have fun with ur wires there a pain in the ass

[alphanumeric]

ok well got the stock head unit out... and I found a wire diagram on this site..but I dotn think its for my year of c class... I have a 2000 c230..

I am hooking up an alpine cda 1004..also with an Ipod controller =)

I got the power hooked up..but I cant figure out the constant (always on) wire to save the memory and settings while u turn the key off.. wth?

also.. whats the deal with teh power anntenna? do I even need to bother hooking this up? its not motor drivin like other cars.. so im guessing its always UP...

and damn! the dang alpine anntenna wire is different then the OEM mercedes one.. crap!!!!

another question... with flip up tvs... what do I hook up the parking break wire up to.. so the screen can be displayed while driving?

it says.. screen OFF for your saftey or something lol

[martattack]

Here's the diagram that I have for a 2000 C230 (Non-Bose) stereo.

http://blauschwarz.home.comcast.net/2000-diagram.gif


Looks like the Constant +12v is Yellow/Black


As for the TV... Normally, people just ground it to somewhere so they can watch it all the time, but if you really want to play by the rules, there is a switch on the back of the parking brake. The Brown/Black wire is the park brake switch wire. It grounds when the switch is depressed.
You can buy an adapter at your local car audio store to convert the antenna plug.

Good luck.
Martin

[alphanumeric]

hey thanks...

I was using my volt meter to find the constant 12v source poking around at the wires.. but couldnt find it.. I was like wth? anyways.. I found out the fuse was blown from cutting right into the loom of wires. and the cutters made a contact..

ya I am not going to be playing by the rules... so I am guessing you just ground it to the chassis right? I tried connecting it to the head units Negative ground wire.. the black one I think it is. thinking it would be the same thing..but it still gave me the NO SCREEN message while not in park .. i dunno

[martattack]

Check your instructions and make sure it doesn't require a +12volt input

[alboogiee]

another question... with flip up tvs... what do I hook up the parking break wire up to.. so the screen can be displayed while driving?

it says.. screen OFF for your saftey or something lol


well my pioneer had the same issue, when i had Good Guys instal it... is the wire green? they say you are "supposed" to hook it up to the break... if it is hooked up to the e brake, cut it and ground it... i just screwed in an open end into one of the radio mounts. very simple. but a biatch if you dont know which wire goes to ebrake.. cuz you got to cut it

[martattack]

Originally posted by alboogiee
another question... with flip up tvs... what do I hook up the parking break wire up to.. so the screen can be displayed while driving?

it says.. screen OFF for your saftey or something lol


well my pioneer had the same issue, when i had Good Guys instal it... is the wire green? they say you are "supposed" to hook it up to the break... if it is hooked up to the e brake, cut it and ground it... i just screwed in an open end into one of the radio mounts. very simple. but a biatch if you dont know which wire goes to ebrake.. cuz you got to cut it

I think Alpine might use a +12v that is hooked up to the Ebrake Light, which is rediculous in my opinion. Would be much eaiser to have it grounded.

[alphanumeric]

man this is so lame.. my ipod does not work with teh alpine setup... but my gurls ipod MINI does!!!! man... I even updated the Ipods bios thingy..and it still does not work.. what a POS

[Maruzo]

Originally posted by Denlasoul
First, if I am not mistaken, you can wire 4ohm speakers to have a 2ohm impedance.

As for the HU, you will need radio removal tools to get them out. See the two slots on the HU? The tools slide in there and "unlocks" the HU. Just pull it out from there.


Hi Denlasoul:

my 98 e320 has 1ohm front speakers, and 2ohm rear speakers. Do i need to wire the speakers any differently before connecting an aftermarket cd/mp3 deck? I've read from nazrat (fellow mercedesshop forum member) regarding the wiring of resistors to bring the ohm reading closer to the tolerance level of an aftermarket hu's amp, but wasn't quite sure if i wanted to go that route.

Here's nazrat's article: http://www.luddite.net/c280/radio.htm

I've also read from pnsji regarding the installation of a nakamichi cd400 unit for a 2000 c280, which seem to have the same Bose sound system as my car.

Here's pnsji's thread: http://www.club202.com/forums/showthread.php?s=&threadid=2029&highlight=nakamichi+install

I'm wondering if i've wired mine wrong because ever since i hooked up my sony hu ( cdx-7705x cd/mp3) i've been getting a constant hissing sound from the speakers. This pestering noise is present at all volume levels and remains the same whether i cranked up the volume or lowered it. It doesn't vary according to engine acceleration either. Which made me rule out grounding/ alternator as a cause.

Any ideas?

Much oliged!

Mars

[Denlasoul]

Yeah, sounds like something may be wrong with your wiring. I would re-check your connections.

In regards, to your different ohm speakers I am not sure. Though it's more than likely that the whole system is wired to a 2 ohm/4ohm load (depending on your OEM system). I know there are many different ways to wire an electrical system to get different ohm loads, but that is over my head.

If you followed the wiring diagram and are using a hi-low converter properly, I have no idea what woud be the cause. But, I would start with the wiring diagram first.

[Maruzo]

Tks for the reply, Denlasoul. What's a high-low converter? Is it like a line converter? My e320 is a 98 model, and according to pnsji, '98 and later bose system and '94-2000 NON bose system do not require a line converter. I've double-checked my wiring and found them to be exactly the way pnsji had wired his c280's nakamichi.

My sony sounds fine. In fact, the volume is much more powerful than before. I use 1/4 of the volume and the speaker are already working at near maximum.

I'm suspecting double-amplification here, since i've found a rear factory amp on my e320.

I might attempt to wring the speaker wires from back of the sony directly toward the factory amp connections.

I've posted a thread on mercedesshop regarding this issue. In that thread i've attached 5 images of my factory amp.

Here's the link: http://www.mercedesshop.com/shopforum/showthread.php3?t=95157

Please take a look at the amp and let me know what you think.

Thanks!

[Maruzo]

I've reread Donbryce's reply on my thread in mercedesshop. Here's an excerpt:

"From your earlier posts, I gather that the trunk CD changer is dead, so probably not connected to the new Sony at all? But what isn't clear is whether there is an external amplifier involved here as well? Could you clear us up on this point. If the Becker 1692 had leads into an external amp, then they would have been low-level inputs, and the wiring to the speakers would go from the external amp directly. Is there a chance you have connected the low-level inputs to the external amp to the (high level) speaker leads from the Sony? That will do really interesting things to your amp, if there is one!"

Sounds like you and him have the same diagnosis regarding my installation. I have indeed wired the high level speaker leads from the sony directly to the low-level speaker inputs to the oem external amp. So, if this is true, what kind of high to low level converter should I get? Will it need to have 8 connections (for all 4 speakers) ?

[pnsji]

Maruzo,

Try to get high low converter if the hissing noise is high. There is definitely a double amplification here:
1 from your sony head unit
1 from bose amps.

[Maruzo]

Hi pnsji:

Tks for the reply. I've placed an order for a high-low line converter at crutchfield here : http://www.crutchfield.com/S-AS49H9s9Wig/cgi-bin/ProdView.asp?i=127OEM2&search=pac+oem%2D2

I looked for the ven 4.5 but couldn't find one, so hopefully this one will do the job.

Btw, is this a fairly straight forward connection of 8 speaker wire leads from the aftermarket hu to the 8 speaker wires leads that goes into the oem amp?

Will i need to adjust the gains individually to remove the hissing?

Also, with this setup, i'm basically bypassing the aftermarket's amp and relying solely on the oem amp to power the speaker, right?

I also thought about wiring the sony hu's speaker leads directly to the oem amp's connector. Is this wise?

I did the same thing on a 90 560sel and it worked beautifully. Not sure if it will work on the 98 e320 because i've heard from some forum members that the front speakers are 1 ohm and the rear 2ohm.


Sorry for all these questions.

[pnsji]

so you know that you have double amplification.
With this converter, you adjust the output from sony head unit to match the input for your amp.
Once the voltage match, you should not hear any noise.

[Maruzo]

Hi Pnsji:

Thanks for the help. I take it once the voltage match, i'll be using the factory amp to power the speakers, and the aftermarket sony's amp will basically have no function at all?

What if I decided to bypass the factory amp and use the sony amp to power the factory speakers? What would be the best route to go about it?

TIA!

:)

[pnsji]

Maruzo,

The thing is that if you want your sony to power your speaker, you have to match the impedance. Check your speaker impedance. Let's say if the impedance of your speaker is 2 ohm, then your Sony head unit better be able to support that.

I personally think that using the high low converter will be just fine.