[tom_h284]

Hi,

I have a strange problem with my audio system in my BMW Coupe 325d (2011) when the temperature outside is 4.0 degrees (39f) or less outside.

From unlocking the car door and getting in, the speakers emit a white noise / static sound. This stops all other audio from working, no radio, cd etc... just white noise. Once the engine is started the sound gets louder and continues.

As the car gradually warms, the speakers start crackling and popping as you can hear the sound from the radio start to come through until finally the audio clears up and the sound is normal again. This only appears to happen in cold temperatures...

Can anyone shed any light on the issue, as I can't understand why the cold weather would cause this.

There is also a cable in the boot, [Image attached] on the left side that is not connected to anything. I'm not sure if this has anything to do with it or what this is even for?

[ctuna]

Cars in the US came with pre wiring for options in the US before 09.
Most likely that is for the CD Changer.
How's your battery weak battery's get worse in the Cold.
Also solder joints that are weak can go open in the cold.
I would try re seating the connectors to the radio as that can
also be a source of problems.

[tom_h284]

Thanks for the reply.

OK so I can probably ignore the cable running into the boot.

The battery seems ok, I've had the car for 6 months now and starting the car still sounds the same as day 1 so I would guess it was OK.

I have tried to re-seat the cables on the back of the stereo, what I might try is leaving the stereo/head unit loose, then when I get into the car and temp is 4ºc < I will try to check the cables at the back and see if this changes anything with the audio/white noise/buzzing issue.

Thanks

[ctuna]

Measure the voltage don't just assume its OK.
Both the resting and alternator voltage.
The battery will be worse before the first start of the day.

[mweisdorfer]

Originally Posted by tom_h284

Hi,

I have a strange problem with my audio system in my BMW Coupe 325d (2011) when the temperature outside is 4.0 degrees (39f) or less outside.

From unlocking the car door and getting in, the speakers emit a white noise / static sound. This stops all other audio from working, no radio, cd etc... just white noise. Once the engine is started the sound gets louder and continues.

As the car gradually warms, the speakers start crackling and popping as you can hear the sound from the radio start to come through until finally the audio clears up and the sound is normal again. This only appears to happen in cold temperatures...

Can anyone shed any light on the issue, as I can't understand why the cold weather would cause this.

There is also a cable in the boot, [Image attached] on the left side that is not connected to anything. I'm not sure if this has anything to do with it or what this is even for?

That's a MOST connection cable.

As cars get older, the electronics get cranky. This is especially true in cold weather. Electronics don't like cold weather to begin with.

When I had an OEM head unit, I got an SOS error a couple times because the logic 7 amp didn't like cold weather.

The first 9-10 years, my 07 didn't have this issue. Again, age has a lot to do with it.