Aftermarket radio install!!!!!

[jcherry]

Ok, I have been working on cars for years my experience comes from the body work side more than mechanical. The thing is a good body man is also a mechanic.

Here is the deal BMW with amps are not simple to make a aftermarket radio work. This is why the radio only sends a signal and does not amplify. When you install an aftermarket head unit it sends the wrong signal to the factory amp which eventually shorts it out.

The solution is a new four channel amp. A lot of people try to sell you new component speakers this is not necessary in a BMW the way the speakers are designed make them sound crisp. It is also hard to find aftermarket speakers that fit the sizes needed.

With that said I recommend a good quality aftermarket amp. There is a way to bypass the amp, but you lose amount of sound you can put out. The best solution is simply a new amp.

Some of the the amps used in BMW are Alpine, HK, and Blaupunk. I suggest alpine or a kicker JL also makes a great one. I used a kicker four channel and it sounds better than the factory set up.

the great thing about a bmw is all your speaker wires are in the trunk I will put together a wiring diagram later but as for now lets focus on what you need to to get started for the project.

First pick out a aftermarket head unit I wanted a double din tv with touch screen. This way I could interface my ipod, and have the controls on the screen. When sellecting head unit keep in mind some will interface with steering wheel controls, but others will not. So you may lose that feature in your car. I am pretty sure most alpine head units will interface but make sure you ask first if that is something you do not want to lose.

Second you will need a wire harness although you will not use the intire harness. You need RCA cables TWO of them. Speaker wire some type of conector. and some tools. You will also need a after market radio trey for your new cd player. I made mine because of the double din although you can find them. You will also need a antanna adapter. Most car audio stores will have this stuff in stock.
Note: with the double din you create the space by taking the sunglass case out and your ac control unit will fit in that space. That is how the navigation units are set up out of the factory.
You will also need an amp kit. You can simple purchase a battery wire in line fuse(I like the hooker audio ones) they also make a breaker box version now so you do not have to replace fuses. a ground wire and use a blue wire to run you amp remote.
Note: before proceding with wiring unplug the battery.

From here you will be able to do most of your wiring in the trunk because that is where the battery is, and your factory wires to the amp. you will have to some wiring for the cd player.

Also the only wires you will have to run is the rca, and remote wire. The remote is in the trunk, but I prefere to use the cd player. If you are going to add subbs and another amp you will want to run your remote from the starter.

now with the cd player folow the wire diagram that comes with the after market wire harness, but do not wire in the speakers cap them off.

The best way to run your rca is to take the dash out and remove the back seat and the driver side year shoulder rest where the back passenger sits the factory wireing harness is there. Run you remote wire and the rca under the carpet and through the should rest. A great tool for this is a coat hanger, and tape. Works better that anything else. It is not easy though because the carpet is tight. Once the wires are in place it hold off on assembling the dash back in place until you have tested the system.

Next it is time to get to work in the trunk. First figure out where you are going to mount your new amp. Remove the old amp put in a box to restore to factory or sell on ebay. They go fast. Next you can get your wire guide out of your service manual or wait for me to post wire guide on here. You are going to slice into the wire harness to the speaker wires going out. use you speaker wire to do this . I take some tape and label each wire as I do this.
Once you complet this you will plug your RCA and remote into the amp. Next you will run your battery wire, and ground wire. make sure you put the inline fuse in place about 12 in fron the battery. hook the amp up.
Note: when doing your install in the trunk remove all the carpet.

Now it is time to hook your speaker wire in the appropriate terminals on your amp, and connect your battery back up.

Now test your system and make adjustments.
Note: if your amp does not have base block built in you will need to purchase base blockers for all speakers expect the large door speakers, and year speakers. Base will blow the others up, and then you will be buying new speakers. You can purchase these at circuit city or best buy. Basically anywhere that sells car audio.

Once you no the system works put everything back together and clean up your work to make it look proffesional.

If you want to put it back to factory, keep the factory amp harness in tact this way you can simply cut the wires you spliced in, and cap them off. it is covered up so no one will ever see it.

In my opinion this is the best way to set up your sterio if you decide to switch it up. I did it to get a better quality sound out of my subs, and also to have the touch screen for my Ipod. It sounds great and is a solid upgrade in my opinion which does not cost that much. one sterio shop quated me $2000 to do what I did, and it cost me about $500

[easyIsle]

Hey ... can you just steal the wiring that the factory HU and amp use?

I mean, the factory HU sends the audio signals back to the factory amp which is in the trunk. Meaning there are wires for it already.

If one cuts these wires in both the dash and in the trunk (where it ran between the factory HU output and the factory amp input), and wires up RCA heads to those, they would perform the same function the new RCA wires you ran would.

Also, doesnt the factory amp receive power when the HU is turned on? Sounds like you can just use that output as your remote wire. Then you dont have to run any new wires at all

Please tell me if/why this wouldnt be possible. Thanks

[jcherry]

Here is my explanation on that
-If you are adding a sub and amp to your factory system then that is the best thing to do. This way you are not running wires. However if you change the head I would run the rca wire from the aftermarket cd player because you are getting a better signal than using a converter.
Note: you are not cutting into the factory wire harness in the front at all. You need to purchase the adapter. and the antenna adapter. The wire harness adapter you wire to the after market cd player, and plug into the factory harness.
- The factory amp will work for awhile, but will start to fail because the cd player is giving off more then a signal. Which overheats the factory amp. Your stock cd player just sends a signal. That is why I opt to change the entire system if you are going to mess with it.
-Note: The BMW cars in general pull a lot of electrical juice. A suggestion I did not include earlyier if you add subs purchase a copacitor. It will help save your battery and alternator.
-The reason I changed the entire system, was due to the ipod, which they make a interface for the factory cd player, but I had subs, and the quility of the rca adaptor is not great which causes some distortion in the sub play. The aftermarket cd player corrected this because of the direct rca connection.
-They make some decent interfaces, but it is like buying a fm modulator for the ipod the sound quality will never be perfect. I want a crisp sound, and have experemented quite a bit with this stuff. This seems like the best option.
- The reason I fan the remote from the cd player is simply one less wire I am splicing into, also I was running my rca's so was already there.
-Another thing to consider if you are adding a DVD unit the wire to ground to the parking brake attaches to the parking brake under the console. That is the legal way to do it. Trust me do it that way. If you alter that, and get into a wreck and your insurance finds out. They will deny your claim.

[tdz123]

Buy an adapter and you can use the factory amp. It won't be as nice of quality, but it requires the laying down of no new wires.

[easyIsle]

However if you change the head I would run the rca wire from the aftermarket cd player because you are getting a better signal than using a converter.
Note: you are not cutting into the factory wire harness in the front at all.

You wouldn't need to use a convertor in my suggestion.

let me reword it.

Stock wiring configuration:
Factory HU (dash) --existing-wires----> factory amp (trunk) ---exisiting-wires---> factory speakers

Your wiring configuration:
aftermarket HU (dash) ---new-rca-wires---> aftermarket amp (trunk) ---exisiting-wires---> factory speakers

My suggested configuration:
Aftermarket HU (dash) ---exisiting-wires---> aftermarket amp (trunk) ---exisiting-wires---> factory speakers

You would just have to cut the exisiting-wires from HU to the trunk, and wire on RCA plugs onto each end (in the dash and in the trunk). Then you have line-voltage traveling to the aftermarket amp along what previously carried speaker-voltage to the factory amp. No new wires this way, as long as you can power the aftermarket amp with the same switched power the factory amp was receiving.

In fact, there might even be an exisiting remote wire that went from factory HU to factory AMP to tell it when to turn on/off. The wiring harness you purchased would contain the wire, if so, and if you can attach it on both ends, Zero new wires (except power wires for the new amp)

(Which is my goal, because ripping out my rear seat, the non-folddown version, and ripping up the trim to run wires is going to be quite a headache. I enjoy my car WITHOUT rattles.)


The only negative would be quality of new RCA wires vs. the factory wiring. But to be honest with you, no one would notice it.

[jcherry]

Would work, and yes loose a little quality, but your right would be hard for the average joe to notice. Which model do you have, I may have an easy way for you to hide the wires. If you are going through all the trouble of changing that stuff out, I would add some nice rca. Thats just me though. Your way will work. One thing though. The factory head unit only sends a signal like RCA the amps coming from a aftermarket headunit will destort more because it is sending a signal and amps.

Buy an adapter and you can use the factory amp. It won't be as nice of quality, but it requires the laying down of no new wires.

This is true it will work, however your amp will start to cut off after awhile. Simply because of how the Factory CD player is designed. It is more like a temporary solution, and then one day your sound will cut off.

[easyIsle]

cool im glad you understand. Its almost always my fault for not explaining properly.


The aftermarket head unit would put out amp'ed signals only on the speaker wires. Tahts why I thought cutting the speaker wires, and attaching them to RCA plugs and plugging that into the line-output of the aftermarket HU and into the AMP in the trunk is required. Some HU's even let you adjust the output voltage of these RCA outputs so it works with your specific amp.


I have a 2002 330i .... I will be installing a KD-AVX33 (single DIN) in the car as soon as I can source all the parts (the DIN mounting cradle, centered plate, and harness.

Would appreciate any sources you use for that sorta stuff. Cruthfield obviously doesnt get the fitment right...

[jcherry]

They do make an interface that is perfectly ok it converts the factory wires to rca inputs, but you loose volume. If you don't blast your music like me this works fine.

[jcherry]

cool im glad you understand. Its almost always my fault for not explaining properly.


The aftermarket head unit would put out amp'ed signals only on the speaker wires. Tahts why I thought cutting the speaker wires, and attaching them to RCA plugs and plugging that into the line-output of the aftermarket HU and into the AMP in the trunk is required. Some HU's even let you adjust the output voltage of these RCA outputs so it works with your specific amp.


I have a 2002 330i .... I will be installing a KD-AVX33 (single DIN) in the car as soon as I can source all the parts (the DIN mounting cradle, centered plate, and harness.

Would appreciate any sources you use for that sorta stuff. Cruthfield obviously doesnt get the fitment right...

Circuit city carries a great wire kit for the the BMW. I was just there this weekend, and all radio install stuff was 30% off because they are closing down stores.

[ckchandler]

what if the 88 735i i bought has a wad of wires where the factory radio should be? even the bentley manual does not tell me which wires go to where. i want to install an aftermarket radio and i am willing to buy a four channel amp because i have no idea if the current amp is even working properly. who has a wiring diagram? please help! my 1 1/2 hour commute without tunes is driving me nuts!
thanks
kyle

[NDubSki]

We are familiar with the e46s... E32s not so much
http://forums.bimmerforums.com/forum...play.php?f=299

Here ya go

[White Knuckles2]

The factory headunit sends a hot signal level to the amp. What we think of as line level (RCA) is a much weaker signal. The factory "sends" this hotter signal with basic, unshielded wiring. There is no need for co-axial shielding to reject noise and hum.

Two options:

You can use a converter to step the factory head signal down for an aftermarket amp input (RCA). Or, you can swap out the head to conventional line-out and run new shielded, cables to the aftermarket amp input.

[mike757]

Did you ever post the wire diagram. Im new to this site