3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
Hello, I have been browsing around numerous BMW forums searching for help on installing my after-market radio. I have installed aftermarket radios in 15+ cars before without trouble, but when I remove my factory stereo, I see wiring I have never seen before. I have been searching around looking for color guides for the wires in there, because the wiring harness I bought (which is the one recommended for the 1990 BMW 325I) does not even come close to fitting the stock wire configuration. Also, aside from a big wire cluster, there were 2 sets of 2 tightly coiled wires with little metal plugs at the end. From the research I did, I understand that I most likely have a factory amp installed, only problem is the car is in the shop at the moment so I can not confirm this. I already checked Chilton guides, wouldn't find a wiring diagram or color guide. I looked in the guides on this website, no luck. Either I am missing it, or it is ridiculously hard to get a hold of. I was wondering if anyone could identify wire colors possibly associated with this configuration, and also a decent guide on rewiring if it would be better this way. The deck I am trying to install is shown here ----> SONY CDXM8810. I have a 1990 BMW 325I 2 Door coupe, manual transmission. I also have a Kenwood KAC-7202 Amp I want to get in there soon as well Thank you very much for the help, and I am glad to be a member of this forum.
Well I am assuming the stock ones suck, so yeah I will eventually put in after-market speakers as well, only thing is I dont have them at the moment, got my Rockford Fosgate speakers stolen out of my old car right before I sold it.
First off, run your own speaker wires, the stock ones go in to the factory amp, the radio and factory amp both use body ground. I'll do a write up to explain how to make use of the factory tweeters (if you have them) in the front all with out cutting anything.
I have never done a rewire before, what type of wires should I get? How do I go about removing the old wiring from the car. Also do I only need to run wiring from all 4 speakers to the deck? I also have 2x 1800watt subs to install as well, but those are easy once the amp is in. I am assuming each + and - for each speaker will be connected to the corresponding wire on the deck wiring, but I discarded the installation manual for the deck, so I am not positive on which wire color is for what. I know that most are the same nowadays, but I don't want to take any chances, and would rather ask a pro. Thanks for your time!
I have come to the assumption I need to cut out the stock amp from the trunk, just clip the wires, and run from each aftermarket speaker, a stereo wire connecting the + and - on the speaker to the aftermarket cd player. I am gonna do that for all 4 speakers, and use the amp strictly for the 2x 1800 watt subs. I am assuming that the stock antennae, constant 12v, switched 12v, is not necessary to replace?
No, leave the amp alone, just run your own wires, just trying to look at the amp is a pain. The factory radio has only left and right outputs. Front and rear fader is controlled by a dial by your hazard switch that adjusts the amps front and rear volume. If you manage to use the factory harness it will sound like crap. Plus the factory amp won't power anything larger than 2 6X9 with out crackling. Been there done that.... The antenna has it's own power supply, like an aftermarket amp it only needs a signal 12V input to function..
Just use a blade connector and hook into the factory power. I'm doing the write up and will be finished with it by sunday afternoon, be patient, or your are going cause more problems than you really want. Short out your factory amp and you'll keep blowing #27 fuse and and your central locking system lights and OBC will be out too.
Don't forget: Assumption is the mother of all f*&K ups....
Thank for the effort man, really appreciate it. I just recently picked up another amp and a capacitor. What is your opinion on connecting the 2 amps' positive leads to a 4.0 farad capacitor? The other amp is a Rockford Fosgate 601S Punch. I was going to use that one for the subs only, and the Kenwood for the 4 speakers via running a parallel hookup. I am *hoping* grounding the 2 amps into the chassis will be ok and not cause electrical shorts.
A 4 farad capacitor is a little over kill, 3 is plenty. To hook any two amps up you must make sure they are both the same amp, and are tri-mode capable. Most amps now are, but make sure or you'll blow both amps at the same time, with a fantastic show of smoke and sparks.
I know for a fact that both amps I have are tri-mode capable.. only problem is that obviously both are not similar amps, as I have a Kenwood 920watt max amp, and a Rockford 1800watt max amp. I guess I can just wire the capacitor to the Rockford which is powering the subs. My only worry is that the system I am installing may be too powerful for the battery/alternator combo I have. I know an easy fix to this would be buying a $200+ Spiral Cell battery and a new alternator which I have no idea would cost me, but I am beginning to run low on funds ;-) I was hoping going overkill on a 4farad capacitor (which came with my wiring kit, <3 Amazon.com ) and hooking up 2 amps to it would be an easy fix, but as you said, assuming is the mother of all F&#@ ups haha. Also, would a 4farad amp actually be too overkill where it will harm the rockford amp? Could I just use a power block and hook the capacitor + wire to it, then run 2 separate wires to each amp from the block?
Last edited by Iceman2k12; 03-26-2007 at 11:20 PM.
Both amps must be the same to safely use tri mode. A capacitor can't harm the amp, in generic terms it's actually an electrical version of an air tank for a pneumatic tool, it'll supply the amps sharp draws so your charging system doesn't take the brunt of it. (helps keep your lights from dimming with every beat) Any deep cycle marine battery with at least 1000 cca will be great. BMWs have a stout charging system. I think there are still a couple od aftermarket upgrades you can buy to bump up the out put. But if you do get one, I would advise a freshly rebuilt alt for good measure.
The capacitor doesn't get hooked up in line, it gets hooked up with a 12V power to the capacitor then attached to the same terminal is the amps 12v power supply. Then on the - side the capacitor gets it's own ground.
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