'91 300E stereo upgrade...where to start?

[caelum245]

I got this car (w124: 1991 300E) about a year back, around the same time my uncle decided to give me some stereo equipment from a BMW his sister had totaled. I want to put it in but I don't have any idea where to start! My experience working on my Benz is 0 (unless you count a carwash), but I gotta start somewhere!

Any help would be appreciated.

Equipment List:

Rear Speakers: Two 5 1/4" Pioneer Premier TS-A530P
Sub: MTX Audio Thunder 4500
Amp: Alpine V-Power MRP-F240
Radio/CD player: Alpine (?)
Deck: Alpine

If pictures are needed, I'll send those later.

[compu_85]

Does your car have the 4 piece stereo? (HU, two amps, and a tuner computer behind the rear seat)

-J

[jha2297255]

id start w rear speakers, the plastic "cups" that hold the old MB speakers wont fit a 5 1/4 but if you cut the 'lip" off you can silicon glue the new speaker in and solder the wires EZ

[caelum245]

Thanks for the pic, jha. I'll see if I can't put that in tomorrow morning.

As for the four piece, I dunno. I found out how to remove the seat cushion, but I'm not sure how to get the seat backs off. I think there's a bolt holding it on there. Also, I'm not sure what an HU is. If I end up figuring out how to undo the seat, I'll post a picture of what's under there.

Thanks

[BodhiBenz1987]

Originally Posted by caelum245

Thanks for the pic, jha. I'll see if I can't put that in tomorrow morning.

As for the four piece, I dunno. I found out how to remove the seat cushion, but I'm not sure how to get the seat backs off. I think there's a bolt holding it on there. Also, I'm not sure what an HU is. If I end up figuring out how to undo the seat, I'll post a picture of what's under there.

Thanks

HU is the head unit, aka the stereo itself. In my 87 the factory set up is Becker head unit with direct power to four coax speakers. Later 124s had the Becker HU with two amps in the trunk powering six (I think) speakers.

[jha2297255]

u push the red clips under front of back seat, in and pull it up and out , 3 10mm bolts hold the rear seat on, both sides and one in center under seat belts

[caelum245]

Thanks for the pics jha, I got the seat up. But I didn't find much. Here are some pictures:

1. Seats removed


2. Under the black covering...not much at the back, but the wires for the amp I'm putting in are supposed to go through a hole near the seat belts.


3. I believe this is a fuse box...I found it under the left rear seat.



4. I have no idea what this is. The covering is like styrofoam and rubber and it covers some wires (and maybe something else?), but I couldn't lift it up without fear of ripping it. I found it under the right rear seat.

[caelum245]

5. And here's the head unit.



I still don't know where to find the amps. I looked in the trunk and found nothing.



I also don't know what or where the tuner computer is.

[jha2297255]

3 fuse box is convenience module, be lucky , the early 300e just has 5029202 wires in abundle ----- dont need 4 stereo

4 that styrofoam thing houses vaccuum pump 4 locks



and ur becker looks like the one i took out, it has no external amps it was 25x2 built in


u shld read this

w124 (89 only?) head unit upgrade/ fader bypass. how to

[caelum245]

Thanks again jha! To be honest though, (I'm a car stereo newbie...) I don't exactly know why we have to bypass the fader switch. I've read about everyone doing it, and your thread was most helpful as to how, but...why?

[BodhiBenz1987]

Originally Posted by caelum245

Thanks again jha! To be honest though, (I'm a car stereo newbie...) I don't exactly know why we have to bypass the fader switch. I've read about everyone doing it, and your thread was most helpful as to how, but...why?

Your current HU is a two-channel setup, with the speakers wired in parallel through the fader switch. Your new HU (almost an aftermarker HU) will be four-channel. Right now you have two sets of wires going into the HU, and you want four sets for the new HU. Easiest thing to do is probably run new wires up from the rear speakers and leave the front wired through the fader. You can certainly bypass the fader entirely, which is recommended by a lot of people. I think the big plus there is 1) you get a four-channel system and 2) by directly wiring the speakers to the HU's amp, you remove a source of impedance and theoretically improve sound quality. Anyhow, what you need is to have four sets of speaker wires to splice onto the HU's wiring harness.

Note: this could be off, because I'm basing it on what's set up in my 1987 ... your 91 may have a slightly different setup. FWIW, I now have the rears wired directly to the HU (no fader) with the fronts still wired through the fader (the fader switch still cuts the front in and out if I choose to use it, but the HU's built in fader also works). Sounds fine. The factory speakers leave a lot to be desired but I don't think the fader switch has anything to do with it.

[jha2297255]

^ like guy above said, the fader gives you 2 sets of speaker outs, most HU have 4 FR FL RR RL benz is weird.

fader also sounds like crap, and mine only goes forward not back, id just rewire it like i did, u need literally 3 feet of wire and minimal disassembly.


PS the fronts actually easier to DE fader than rear, wires r right in radio hole just yank em out! both green/black w white euro plugs