Aftermarket Amplifier install?

[munchichee]

My friend just got a 94' 540i and I installed an aftermarket head unit to the stock speakers which of course didn't do much. He went and got some 5 1/4" coaxials from after I told him component set so that's what I'm installing.

Anyway, I was wondering with the common ground wiring, can I tap into the factory wiring at the old amp and wire the new amp normally, or do I need to run new wires to each speaker along with the rca's? For the time being now I'm only hooking up the four 5 1/4" to the new amp and just leaving the rest alone. - Thanks in advance for any input on this

[Kamil]

Maybe this can help:
http://www.bmwe34.net/e34main/upgrade/speakers.htm
http://www.bmwe34.net/e34main/upgrade/Stereo_wiring.htm

[munchichee]

thanks kamil - I have read that site but it doesn't specify exactly what needs to be done when changing amps. It has a "coming soon" section for what I need to know. I'll still need that wiring diagram but I wasn't sure how the common ground setup would be without components and crossovers.

[Mobius]

It says it all. The second link lists what each wire in the stock amplifier harness is.

You need to run RCAs from the deck. If you were feeling industrious, you could solder some male RCA connectors to the stock radio harness at the head end and amp end - thereby using the existing wiring as an RCA cable - but I can't guarantee that this is going to sound the best, as those lines are shielded like most RCA cables will be.

Then, at the amp end, just lop off the stock amplifier connector and use the list mentioned above to connect each speaker to the amp appropriately. This also means that if you're planning on using a component system, since all the wire pairs for each speaker end up at the amp there, you can mount all the passive crossovers in the trunk - which is way easier than finding space inside doors and whatnot.

Also, if your car is a 1994 - you don't have to worry about common grounding. That's only a 'feature' of 1993 cars (like mine.. grr). Luckily, all the grounds were made common with solder joints about a foot down the wiring loom from the amp connector. Once you unwrap the loom and break those common grounds, you have all 10 wire pairs independent and ready to be connected to your amp.

Edit: Sorry, I forgot that you said he already has an aftermarket deck wired (and working with, I'm assuming) the stock amp. If the deck's line-level outputs are already wired to the stock amp, all you need to do is solder on some male RCA connectors to the appropriate wire pairs (the ones in the top sections of the list) and connect 'em up to the appropriate channels on the new amp. Remember that the middle pin on an RCA connector is positive.

[munchichee]

Thanks Mobius -

The details about the common ground is what I needed - that saves me a lot of time using my "made in taiwan" trusty DMM to test those "if these don't piss em' off..." wires - brought to you by your friendly "That'll make em' bring it to the dealership" BMW co.

Just like my friend, the car doesn't live with me - that's why I'm not outside figuring this out myself - but I used to install & I want to avoid install headaches during the short intervals I get to work on it.

After I installed a head unit using only pos+ speaker wires, I was trying to find out if the speaker wires from the plug at the factory amp can hook straight up to an aftermarket amp. I guess I got lucky on having the common ground meet right there! (I didn't find the info about the 10 grounds connecter in the harness -unless you meant by looking at the diagram...but thanks!) Also, I'm running rca's from the nice 4V preouts on the new HU to the new amp(s).

I got him some 5.25" Clif Designs components today (so the best buy 5.25" coax he got are going back)...I've heard good reviews on Clif stuff recently - especially for the quality/price ratio (we'll see). My buddy's itching to replace all 10 factory speakers but so far no 2.5" mids on this horizon. My electronics distributor said good luck on that search!

Quick Q's
Can 6.5" components fit? If so, how much modification does bmwe34 mean by "a little" (http://www.bmwe34.net/e34main/upgrade/speakers.htm)?
Where can you find 2.5" mids for the dash? - Is this a lost cause?
Has anyone done or seen any creative installs using the 10 factory locations(or mods) besides just components?

Ummm...yeah sorry bout that strange outburst and this extended post but I just finished a Bose nightmare in an the same person's Infiniti I30 (ripout, rewire, reinstall & the whole shebang)- only for it to get repoed while building the custom enclosure with every last thing,... and so here we go again!