Stereo/Common Gnd?

[busdriver]

In my quest to procure a 535i I happened upon an 87 325I 5 spd sedan sitting on the coner just down the street. 81k, second owner, slightly neglected but under the dirt very nice condition. No maintenance history but for $2800 I jumped on it. After all fluids and a timming belt, no regrets, these E-30's rock, what a fun and practical little machine (for me anyway). So, the origional radio was toast (cassette jambed). I believe this car has the upgraded sound system with seperate tweeters (the fronts being up high on the doors). My objective (KISS) is to replace just the stereo and utalize the existing amp and speakers. Are these older speakers/amp worthy. The wiring appears straight forward until I get to the speaker wires, just two single wires to the fader, then four wires comming out of the fader (I'm assumming they then run to the amp and on to speakers). Can an aftermarket CD/radio be tied (with the positive leads) into the factory wiring downstream of the fader where four wires are available, and then ground to the chassis the negative speaker leads? I'm not looking for concert sound, just descent sound. Any advise would be appreciated. Also the trans leaks way to much for me. Is this common, is it a big job to reseal? Is it advisable to replace the guibo (yes I have read the BMW buyer,s guide 3 times) at the same time. It appears to be in good shape. Thanks for your time.

[carolinus]

From an EE standpoint, yes you can just replace the stock stereo with an aftermarket one and run the 4 positives to the speakers and the 4 negs to ground.

I strongly advise not doing that, though. With modern equipment not designed as such, it will degrade your quality.

Instead, I would recommend running new wires to each speaker and going from there.

To replace the two sets of speakers up front I woud just get a 2 or 3 way speaker all in one unit. It will sound the same or better, and be much simpler to handle.

Besides, today nice speakers are pretty cheap, and you don't really know if what you have is blown already if you haven't tried them out.

[busdriver]

I agree. Installed an old stereo I had sitting around. What a waste of time. Off to Fry's for some modern equipment.

[Jared at Pelican Parts]

Replace all the wiring in the car. It's much easier than trying to make the stock wiring work with modern components.