87' 300E fader bypass / rear speaker help

[speedylizard]

OK here I go I'm putting in new CD player for now and want to use the original speaker wier for now till I put in amp.

I have all the power and ant. wires figured out and i though to dissconnect the fnt speaker wires from clip in console behind player and then use the connectors to hook up the rear to and then at the fader I'm confused. I can't get the sound out to the back. I've used a 9v battery to find the path but no sound.

ok here are the color of wires at fader....could someone please tell me what I need to do to use the original rear speaker wires.


grey/ black
yellow /black
green /black
red/ black
red brown
brown white
all browgrey /blue (i think is the hot for the illumination) just cut this. right?

ANY HELP WILL BE USED AND HOEFULY ASAP.........THANKS

[erubin]

My understanding is that you should not use the MB fader wheel with a modern head unit. If your headunit has four amps you should wire the 4 speakers directly to it and bypass the fader. You already have the needed wires going to the back speakers so you can reuse them. The 9V battery techn will work once you hook up to wires without the fader in line. This will also help you keep everything in phase by looking at the cone movement. Some people have the front and rear speakers 180 degrees out of phase and don't even know it. Does do some weird things to your eardrums because of some strange noise cancellation.

[pentoman]

Actually, I ran with speakers in phase (all +ve's connected to +ve's etc) for the first month or two with my Boston Acoustics front and rear, but found they cancelled each other when I sat in the drivers seat. I've since rewired them so the rears are out of phase (-ve's connected to +ve's) and find the sound much better, but this is in a 190E using the dash speakers, and maybe it's just my preference.

speedylizard - If you don't plan to go too loud, you may be OK using the built in fader, but if you have a fairly high power head unit, and definitely if you're using an external amplifier, then as erubin said you should put in new wires. You could extend the existing wires from the fader switch to the back of your new head unit, or add entirely new ones. Oh while you're at it, why don't you add a subwoofer, and an amp, maybe an equalizer.. this is how it starts.. :p

[csnow]

You can simply leave the existing fader wiring alone for now if you like. That is what I did.
Save yourself the trouble in the interim.
Just attach the existing speaker wires at the head unit to either the front or rear channel on the new unit, and continue to use the factory fader wheel.

Set the fader on the new unit all the way to whichever channel you wired.

If you are using the factory speakers, there is more than enough power coming out of any modern unit to drive all four.

If you get an external amp and new speakers later, you will probably want to run new fatter speaker wires to everything anyways.

I would, and did, bypass the fader altogether. It can't handle a lot of power and might exhibit noise over time, even if you leave it alone. I wired all four speakers direct from my Alpine to the speakers. Running the wiring was easy. It'll take about a day for the unexperienced.

[MTI]

I agree with Tony, if you're upgrading your system, run new wire from the back and the dash and bypass the fader wheel. There are plenty of grommet access points from the trunk through the rear seat to get wire up front and the MB carpet pieces make it even easier.

Take a look about 2"-4" down from the top of the back seat on the passenger side, behind the seat. There may be a hole there that they ran the vacuum hoses thru. That's where I ran my speaker wire, and on the driver's side I ran a 4-gauge wire for the amps in the trunk. Try to keep the speaker wires(all wires, really) out of the way..... basically out of the way of people's feet who may be sitting in the back. Lastly, I wouldn't run anything smaller in gauge than 16 for speaker wire.