Change out the Bose system in 03'

[RAZOR1]

Hey all..

I have read and reread searched posts.

Can I remove the factory CDR23 and install a after market head unit? I want to use the factory wiring, which according to Metra, they supply a harness for V.W. By using the 70-1787 and flipping the yellow and red wire. This will allow the head unit with out messing up the computer.

I really want to use the factory wiring for the speakers? Is the a harness for this MOST system? Fiber optics from what I understand can not be spliced. Is there a way to connect the MOST to an after market speaker?

Thanks for any info.

Joe

[RAZOR1]

No one has any info/ideas?

I can't get the stealership to pony up, no one I know knows anything.

I just don't want to mess up the ECM/Computer.

Joe

[RAZOR1]

Okay. After more research it seems the speakers ARE not connected by any F/O wires. They are connected by regular speaker wire. So this is a plus as I may not be able to change out the head unit but I can up grade the speakers.

Now to research the Amp...

[carlson]

Okay. After more research it seems the speakers ARE not connected by any F/O wires. They are connected by regular speaker wire. So this is a plus as I may not be able to change out the head unit but I can up grade the speakers.

Now to research the Amp...

Keep in mind that at least the rear speakers are a different resistance than conventional auto speakers. If I recall correctly, they are somewhere between 0.6 and 2 ohms, whereas most auto speakers are 4 ohm. Use an ohmmeter to check speaker resistance from the harness while disconnected. I think it may be difficult to find acceptable aftermarket replacement speakers that will perform correctly with the factory amp. I bought the later model rear speaker box to put in an earlier boxster, and found that I had to rewire the speakers in series in order to increase the resistance to a more conventional level. You have the opposite problem where the new speakers may be higher resitacnce than the amp is designed for. I would imagine that you would get the best sound from the original amp with the original speakers than trying aftermarket speakers with improper resistance for the original amp. My car does not have fiber optic cables, but I believe the fiber optic cable on newer models may only connect the head unit to the amp, which may make replacing just one part nearly impossible.

[RAZOR1]

You are correct Carlson. The F/O cable simplr connects the head unit/amp/cd changer/phone together.

I had the rear shelf box out yesterday afternoon. It is loaded with 5.25" woofers and 1' tweeters.

I didn't think to look at the Ohm resistnace, but I will check aorund a little more.

Thanks for the info..

[atmorris]

You are correct Carlson. The F/O cable simplr connects the head unit/amp/cd changer/phone together.

I had the rear shelf box out yesterday afternoon. It is loaded with 5.25" woofers and 1' tweeters.

I didn't think to look at the Ohm resistnace, but I will check aorund a little more.

Thanks for the info..

CDR23 is MOST BUSS system device. FO connection between HU and Amp. Speaker connections are wire - FO connections can't be used between an amp and a speaker..FO carries data, not current. HU is the driver of the MOST buss, if removed, the entire MOST system is useless....so.... If HU is changed, amp will have to be changed out also. Not 100% certain about the Bose drivers, but the M490 system drivers are all 4ohm, I suspect the Bose are as well. If you re-amp, go for a bit more power. The system is underpowered with the top down. 60 watts per channel or more would be better. If you can handle the mod, put 6 1/2" drivers in the doors, it improves bottom end tremendously. The 4 1/2" dash speakers tend to be very bright, a speaker that is a little "warmer" will sound better up there. Check this out, it might help:

http://www.renntech.org/forums/index.php?showtopic=9613

Andy

[RAZOR1]

Thanks Andy.

Only question I still have is...

What will this do to the computer/ECU of the vehicle. I have read that it will make many error codes and such. That I have to go to the dealer and have the stereo system "turned off" in the vehicle computer. Then on another forum I have read that it is no big deal to change things out. In fact I think I saw a wiring diagram for the speaker wires, hot, memory and ground somewhere.

Any Ideas?

Thanks Joe.

[RAZOR1]

In the event anyone is still keeping up with this thread..

I talked with the owner of the local stereo install shop in town. He made a few calls and has been told that removing the factory head unit and amp should not hurt the computer.Nothing left to do but do it. Will post the out come..

Joe