I have 01 330Ci and I have had major problems with noise getting into my system (alternator whine I think) from my local shop that installed the system. They are one of the best stereo shops in town and they have said they tried to remove the noise but couldnt. I have searched the forums and have seen a lot of threads about 330Ci noise so I suspect its a fairly common problem. What I want to do is to have the shop take everything out and start from scratch, but with certain install instructions instead of them doing a normal install.

For the people who have solved the problem in their 330 (or know someone who has), what instructions do I need to give them to eliminate the noise? Such as where to run the wires? Where to ground the amps and HU? Certain types/gauges or power wires or RCA wires? Anything that would help?

Thanks in advance.

LOL, i highly doubt that they would appreciate you telling them to remove it and and reinstall it. I would laugh in your face with a blunt NO.

But, assuming they are one of the best shops around (which they should be able to fix this problem,) here are a few tips to get rid of alternator whine.

Leave the system as is.

Disconnect the rca's from the amp, if the noise remains, the problem is at the amp, speakers, or speaker wires (outputs). If the noise goes away, its upstream (deck, wiring, signal processors, etc)

From working with many noise problems with BMW's, I can remember a few that fixed the problem.

Try to reground the deck to a better ground. The factory wiring harness is the noisiest place in the car. You can also try running new accessory or constant wires from the ignition harness or fuse box. Make sure that deck is grounded well or it will try to pull ground from the amp or rca's (noise)

If you kept your factory deck, the most noise free way to wire the new amp is as follows. Run your standard 4 channels rca's into the input of the amp (low level). Then wire the other side of the rca's (cut off the ends) to the low level outputs of the deck. Either at the deck or at the factory amp input harness.

Of course, the essentials:

Run the power, ground, and REMOTE wires on one side of the car. All signal wires should be down the other side. Use expensive shielded RCA's for the 4 channel amp.

Try those tricks and let me know if you need more help.