Audio Volume Control Help Needed

[wstr75]

Yesterday when driving over a highway bridge to road transition (bump), the radio volume control stuck at its setting and cannot be changed by the radio button or the steering wheel buttons. In the past month there have been momentary (about 1 second length) episodes where the radio temporarily cuts out similar to when a Sirius XM signal is blocked by trees.

It is a standard E46 navigation head set. I replaced the display about six years ago to eliminate dead pixels.

Anyone know what has likely gone wrong? What to do to fix it?

Bill

[Oli77]

it is strange that both the physical button sitting on the circuit board of your radio and the steering wheel volume control have lost control of the volume. The temporary cut outs make me think that you have maybe a bad contact back there (i.e., behind the radio).
You can move the radio button but it no longer controls the volume is that right?
Or, is your volume button physically stuck.

[wstr75]

I can move the button and sound level does not change.


The radio twist button directly manages a rotary potentiometer of some sort that changes a circuit voltage setting. The steering column buttons probably change a circuit voltage setting. Two separate controls of the same circuit no longer can change the circuit voltage. One is physically attached to a circuit board (radio button) and the other via external wires. I can see the steering buttons connection possibility, yet the radio button should continue to function.

Maybe a solder joint in the voltage control circuit has detached or a component has died.

[wstr75]

Anybody know if an original e46 OEM replacement navigation radio head unit can be swapped into my car without coding to accept the new/old radio?

[SoCalZman]

It is a standard E46 navigation head set. I replaced the display about six years ago to eliminate dead pixels.


Bill

Sorry for going on a tangent, but my nav display is slowly losing pixels. Can you provide some details on replacing the nav screen? (where did you get the screen, followed a DIY? was it easy? etc)

Somewhat on topic. I have read threads of people with the non nav headunits upgrading to the OEM nav units and they never mention anything about needing to code for the car. Mostly griping about having to wire stuff to the trunk (which we already have).

[wstr75]

The Jimmy mentioned in this link is the party I bought my screen. He was formerly an Alpine factory technician.

https://xoutpost.com/bmw-sav-forums/...onitor-21.html

[cornercarver]

Yesterday when driving over a highway bridge to road transition (bump), the radio volume control stuck at its setting and cannot be changed by the radio button or the steering wheel buttons. In the past month there have been momentary (about 1 second length) episodes where the radio temporarily cuts out similar to when a Sirius XM signal is blocked by trees.

It is a standard E46 navigation head set. I replaced the display about six years ago to eliminate dead pixels.

Anyone know what has likely gone wrong? What to do to fix it?

Bill

At least two or three times over the last couple of years my radio / nav just stopped working for no apparent reason. No functionality whatsoever, but if I shut the car off and wait a couple of hours or until the next day, it works fine... like nothing happened.

Any change in yours after waiting a while?

[wstr75]

Ok, this is embarrassing because I should have done this first and not gone on an assumption spree.

I bought a used head unit with bad pixels off Ebay and yesterday was gearing up for pulling the radio out of the dash, pulling off my display, grafting it onto the Ebay head unit and re-installing into the car. I thought, hmm, maybe I should try this before tearing things apart: disconnect the battery and let it sit overnight. I did that and be doggoned, it resolved the volume control problem!!

Saying this while beating my head on the wall, "Always disconnect the battery and let sit overnight whenever some electrically related gremlin happens!"

[fredo]

Very interesting. Glad to hear this has been solved.

[wstr75]

Update:
The problem was only temporarily solved with disconnecting the battery. The situation got steadily worse to where it would not go more than 10 minutes without jumping to loud and the audio buttons not controlling sound anymore.

After trying a number of remedies and replacements, the problem has now been solved. I bought a Harmon Kardon amplifier off Ebay, swapped out my original HK amplifier and the problem went away. Note: the HK amplifier for convertibles is different than sedans.

I had to disconnect the battery after replacing the HK amplifier as the system did not recognize it when I started the car. The K-Bus apparently requires a reset to correctly handshake with all the components.

Another problem showed up in yesterday's work: the top button for raising the convertible had a steady red button. The car has had its hardtop in place for the past two years. To get at the HK amplifier the hardtop had to be taken off. (HK amp is installed behind the driver's side rear seat armrest.) I drove the car home with the top down after hoisting the hardtop in my barn. When I went to raise the top after finishing the HK swap, the top red light came on. Searches on the internet pointed to the windows needing to be operated up and down to get the system synchronized. I then pressed the all windows up button and no windows operated. Next I raised each window individually. I then pressed the all windows down button and only the back windows went down. This went on for three cycles. On the fourth cycle the system recognized the all down/up button for all four windows. At that point I went on to raise the convertible top without incident (or red button).

Now to put some miles on the car so the state inspection can have an emission history reading since the last battery disconnect.