JayDee4711

I have the stock head unit in my 2001 E320 Wagon. AFAIK, it would be the ALPINE CM2299 that probably all non-GPS US models came with. Starting maybe a year ago, the volume control became flaky. When I turn the volume down, it may go up or not change at all. The steering wheel control operates as desired.

I have pulled off the knob and tried cleaning the controller with compressed air. Did not dare contact spray, since I am not sure if it is actually an optical controller... Can anyone help? Is it time to think of a replacement?

C280 Sport

I wonder if there is a way to get rid of the radio volume when driving. Faster you go the louder it gets.

fosmith

These units are prone to this problem. Here's what I did to (largely) fix this on mine. Get a set of removal keys from ebay or at the dealer - they are cheap. Remove the radio from the dash. If you don't have the security code, don't unplug the wiring harness. Pull the volume knob off and holding the radio in the vertical position, squirt a small amount of elecrical contact cleaner down the volume control shaft. Turn the shaft back and forth a few times. Squirt a little more cleaner, turn it a few more times and it should be good again at least for a while. If not, you'll probably have to replace it. Make sure to put a towel under/around the radio so you don't get the cleaner on the console.

Fred

JayDee4711

@C280: I found a post somewhere on this forum saying that the stealership can program it when pressed persistently enough. I agree it is a nuisance, but fairly minor IMHO.

@fosmith: Thanks for the suggestion. The electrical cleaner is what I meant with contact spray. So it does not seem to be an optical controller after all. I do have both the removal tools and the code. The parts department at Fletcher Jones in Fremont, CA looked the code up for me (free of charge!!). Those guys know their job. I still drive the extra 20 miles when I need something hard to find.

I will try contact spray and report.

RichardM98

Most of the newer Becker radios (Alpine?) have a feature called GAL (Graduated Volume Level?) which cause the radio volume to increase as the speed increases. It's often user programmable so check your radio manual. Usually settings 1-5 determine the speed it kicks in and setting 0 turns it off.

Polar Bear

I would be interested to see if this is indeed the case - I don't recall seeing it in the manual for my 1999 or 2001. I thought it had to be done using SDS.

JayDee4711

Finally found the time to pull the head unit today. As promised, I am reporting what I found: Applying the electrical contact cleaner with the head unit installed helped a little, but there were still dead spots. Today I pulled the head unit and held upright. No need to even disconnect the cables. This completely fixed the issue -- for now, at least. Thanks Fred!

While I was at it, back in February, I treated the AC control unit with the electrical cleaner, too. And guess what! Four of the five buttons that had a bad contact got a second life out of it, and still work like new three months later. Only the left Auto button needs two or three invitations until it cooperates. Still better than before -- it was completely dead. This may be interesting news for those who have trouble with the AC buttons, too. Much cheaper than a new or refurbished control unit.