aftermarket stereo wiring

[Jared S]

I'm installing an aftermarket CD player in my '86 535i and I'm not sure how to wire up the speakers. Are both the front and rear factory speakers driven off an amp? Can the factory speakers be wired into an aftermarket CD player easily or do new speaker wires need to be run to the speakers?

[Shawn D.]

You're going to need to run new wires one way or another: from the head unit to the speaker wiring harness connector at the factory amp (under the rear deck in the trunk, on the left) or from the head unit to the speakers directly.

[Snakeyestx]

+1

Also, plan on running a new 12v constant wire as well. The original 12v wire can't really cope with newer 40/50x4 headunits and will cut out constantly at higher volumes.

[Scottinva]

I run the factory 12v, I have yet to have a problem. I actually use to run my wideband from it too without problems.

[mooseheadm5]

Despite what Scott says, I would strongly suggest running a new 12V constant wire. Nothing like blowing a fuse when the bass hits. The stock 12V constant wire was designed to provide a very low current feed for the radio memory, while the higher current was handled by the 12V switched wire. New stereos use the switched power as a low current signal wire to turn on, while the higher current feed is taken from the 12V constant wire.

Also, screw the factory amp. The amp in your head unit is probably better and more powerful. Just run new wires to each individual speaker.

[joegreen]

mine also has a kenwood aftermarket cd player in it, i had it wired up at competition sounds in corpus christi, they didnt have to do any thing but replace the conector for the stereo and trim the opening a bit to install. sounds great too!

why should you have to run wire back to the trunk? just asking cause i dont know...

[Shawn D.]

why should you have to run wire back to the trunk? just asking cause i dont know...

It's only a "have to" if you don't run the wires directly from the stereo to the speakers. This is because the wiring from the factory stereo to the factory amp is floating ground; the wiring from the factory amp to the speakers is not floating ground. The factory amp is in the trunk. Thus... 2+2="have to"

[joegreen]

why should you have to run wire back to the trunk? just asking cause i dont know...

It's only a "have to" if you don't run the wires directly from the stereo to the speakers. This is because the wiring from the factory stereo to the factory amp is floating ground; the wiring from the factory amp to the speakers is not floating ground. The factory amp is in the trunk. Thus... 2+2="have to"

i like that 2+2=have to bit and i call ed the installer back up he said he did actually run some wiring in my car it was the guy at the counter told me they just changed the plug

[Jared S]

Thanks guys. I think I'll take the route of running new wires to the amp in the trunk.

[Shawn D.]

Thanks guys. I think I'll take the route of running new wires to the amp in the trunk.

Note: you will not be running new wires to the amplifier -- you will be running new wires to the speaker wiring harness at the amplifier. The factory amp will be out of the picture.

[87royal]

word

[Jared S]

Yep......got it.....thanks.

[BigMac]

I recently had a CD player installed at CarToys. I have to admit they hooked me up. I believe they had to rewire everything from the CD player to the amp. Only charged me for a hardwire which was $25. Should have also charged me for an amp install.

Apparently the factory center-fade causes issues?

The car had a Sony Xplod deck in it when I bought it that soon Xplod'ed. The factory center-fade hadn't been bypassed and in order to make the deck work they had in essence bridged the amp in the deck.

[mooseheadm5]

Yes. The fader only works with the common ground system using a 2 channel amp. If you replace that with a 4 channel amp and still have the speakers on a common ground setup you cannot use the fader.

Only cars with premium sound had an amp in the back.