help! I can't get my old alpine HU back in - PeachParts Mercedes-Benz Forum

hedpe · #1 11-03-2003, 04:22 PM

Alright guys, I'm in a desperate situation. I need to get my old head unit back in the car and the people who installed it are booked up until my car is getting taken away. So I don't have anyone to put it back in. I'm quite mad b/c I had scheduled an appointment and taken it up there but they said they needed an unlock code for it b/c they thought I wanted them to put in the old becker when I specifically said alpine. Kind of frustrating.

At any rate...heres my major concern.

I don't know who originally did the work but they put an alpine 4-channel amp in and ran rca's back to the 4-channel amp. I recently removed the 4-channel amp and sold it not realizing how hard of a situation it would leave me in. So all of the speakers were hooked up to the alpine amp in the trunk.

How do I hook the speakers up to the alpine HU to use the pre-amp on it? Do I have to run those speaker wires all the way up to the front of the car or are there connectors that should be left over from the bekker that I hook it up to?

I don't care about ripping the RCA's back out, I just want to get the speakers working and sound coming out from the HU. How do I use the preamp and do I have to run those speaker wires back up?

Thanks guys.

hedpe · #2 11-03-2003, 04:50 PM

Can you guys identify what the circled set of wires is? Maybe this will help me find the speaker wires. You don't disconnect the old speaker wires when you install a 4-channel amp do you? I won't have to run the speakers wires up to the front will i? Help

Gilly · #3 11-03-2003, 05:37 PM

I can try getting a good answer for you after supper

(this evening) if no one else knows off the top of their head.
They may have cut off the speaker connectors by the looks of it. Can you tear that gray foam tape off and post pictures again?
It'll end up being 2Xtwo wire connectors, i can get the wire colors for you. They then feed into the fader in the center console.

If you look at those 2 black connectors (in the #2 image you posted, the left and right circles), you can see on the back of the original radio where these plug in, neither of these are for the speakers. The speakers are just 2 terminals each, one of the harnesses on the car is white, the other is black, and you'll see where each color goes on the back of the radio (color coded).
Those 2 black connectors are for power, ground, lighting, etc. I can tell you what each wire does if you need to know. I believe this is for your 89, right? I know you don't need a radio code, and I don't believe anything special at all will be required to make the radio work again.

Gilly

ned2683 · #4 11-03-2003, 05:59 PM

i think to try to answer one of your questions:

if u had all your speakers hooked up to a 4 channel amp in the trunk and u sold it. and now u want to use your HU's amp, then yes u will have to run wires from those speakers to your HU.

also from looking at the picture i can only identify the blue as the remote lead wire. red is either ignition or constant 12 volts. usually ignition. and the yellow is usually constant 12.

Gilly · #5 11-03-2003, 07:49 PM

After looking at the images you posted I realize this is for your 92 500E (124 chassis, duh!).

Yes you will need the radio code.

This is a 2 piece radio, the tuner/receiver is in the trunk, this is where you will need to reconnect speakers (and hope things aren't too hack'd.

To install the head unit, I have wiring info, should be pretty straightforward.

You'll notice the one white connector with the metal tab on it, there is a tab on the bottom of the back side of the radio, that one connects there (I know I saw the wire for it in one of your images).

The one connector with the 4 wires going to it, just connect to the radio in the correct spot. The brown wire is gound, the black is power from fuse 1, the gray w/blue stripe is illumination, the red w/white stripe is power from fuse 9.

The other connector I believe is a 2 wire, the gray w/yellow stripe is the speed input for the variable speed-dependent volume control, the black w/yellow stripe is a mute signal for the factory cell phone.

I believe the tuner amp in the trunk is on the right (passenger) side. Hoping everything is still installed and you can just patch wires together.

On the back of the radio itself there is a small metal box, you should be able to find the connector that plugs into that as well, that's the data feed to the receiver-tuner.

Gilly

hedpe · #6 11-03-2003, 10:20 PM

Gilly: I'm not re-installing the factory becker, I'm re-installing an 96 Alpine HU, so it shouldn't need a code correct?

I think the fact that i'm installing the alpine and not the factory becker changes all of your instructions. I'm gonna have to splice wires and connect the grounds and everything.

As for the rear speakers, is there any way I can check to see if the speaker cable up front is working for them? I really don't wanna run speaker cables up

I can't figure out how they ran everything up.

Gilly · #7 11-03-2003, 10:48 PM

George
Well, hopefully my instructions will at least help get this other radio wired (power/ground, etc) If you need me to, I can figure out which one is constant power source (for radio memory and clock, if it has that) and which one is switched power.
I'm not familiar with the radio you mentioned. If "96" is the year then it takes a code. If this is what the radio is, do you HAVE the code (let me know).

Just leave the wire alone for the anti-theft alarm that I mentioned (with the white connector) but I'd tape that metal tab with electrical tape.

If you can remove the speakers it may make it easier to wire them to the radio, this should work if you will be happy with front speakers only. This assumes the amp is built into this radio you want to install. Can you post an image of the front and back of the new radio?

If this new radio uses the typical MB speaker connectors you'll probably have to get speaker connectors like what MB uses (your cars speaker wiring must run back into the trunk). I have a couple of them around I think, but you said you need this done fast.
You may also be able to find the ones that plugged into the receiver/amp in the trunk.

Gilly

Gilly · #8 11-03-2003, 10:53 PM

Oh Man, if that IS a 1996 radio, it uses a different style of connector. I can help you sort it out though, let me know man.
Radio is what, out of like a 96 C Class? i think all 96's used the same radio, i got diagrams around here somewhere. Let me know what you got and it'll probably be tomorrow night before I can dig into it. BUT you HAVE to have the connectors for the new radio, you got them? If not I think you're sunk.
Not sure about the antenna plugging in to the new style radio, don't know if there's an adapter you can get for that or what.

Gilly

hedpe · #9 11-04-2003, 01:15 AM

holy crap dude, i just spent 3 hours getting the old alpine back in.

Yeah it had a completely different connector...you know what that means....

i had to cut all the ground, remote, power, speaker...everything and resplice it and reconnect everything.

3 hours!!! and I had NO clue what I was doing. I was just touchin wires (with ground and power in mind

)

Before I started cutting the ground, remote, and power from the new connector, i connected my new alpine to test which speaker wires were active. I found the front four speaker wires via touching power and grounds appropriately to test for sound. I did not find any rear speaker cables...I assume this is because the amp is in the trunk/back and mercedes therefor did not pointless run rear speaker wires to the front?

Thats okay, insurance is going to have to deal without rear speakers.

I was just connecting colors and minding which wires were connected where. Afterall I was swapping alpine for alpine so the colors were all the same and connections all the same except for the main connector!!

Man that would have saved 2 hours atleast.

I'm just glad its over. Thanks guys!!!