Radio Volume Control jumping..

[Tarydesign]

I have finally decided to pull out the radio and check what causes the volume control to jump (sometimes in the wrong direction) when you adjust the volume. This seems worse when you start the car and for the first 10 to 15min things are at the worst, thereafter the volume seems to work just fine. I have noticed that many MLs have this problem, my ML270 was sorted out under warranty by the dealer, and every ML I have test driven has this problem.

Does anyone know what the problem is? Can I just pull the radio out (with the two radio levers)? What do the two levers look like, I have a few I'm going to try, but is there something special abou the ML ones?

[cmitch]

Fluctuating volume is caused by a feature that is supposed to adjust radio volume for road noise, etc. However, it's results are less than desirable and down right, annoying. The dealer can disable this feature through the AAM, but they have to put their computer on it to do so. Some dealers do not charge, others ream you for an hour of labor. I think you can disable it by unplugging the microphone that is located on the roof trip computer. I've not done mine yet, but I've heard it works. Do a search on this forum for that.

[pointman]

Every ML you have test driven does that? Really? Not an exaggeration? And how many ML's have you tested?

[Tarydesign]

The automatic volume control works perfectly, its the knob that makes the volume 'jump' as you try to turn it. When starting the car, and you try to adjust the volume, it doesn't matter which way you turn, the volume goes UP!!

This is my second ML, first I had the 270 (which was repaired under warranty for the same fault) and when the agent couldn't get the engine to start (after rebuilding it) they offered me my money back and I went looking for another ML. I must have driven +_10 more before I found the ML430 which I now have. ALL of them had the problem to some degree, but fortunatly mine goes away after 10-15mins drive time!!

I'm not sure, but I think its the audio 10 ??? With the Bose speakers and sub-woofer.

[Mike's ML]

Tarydesign, you are asking for advice but you don's tell us which radio you have. The fact that you have an ML270 makes me think that you are not located in North America. Please update your profile to show which ML you have and your location in the world. I have two ML's with North American MCS1's dating from 1998 to 2005 and have had no problem with the volume control.
Thanks,
Mike

[Bigburgundy]

he doesnt have the 270 anymore. he has the 430...which he stated above...

[Gene Horr]

Originally Posted by Tarydesign

ALL of them had the problem to some degree, but fortunatly mine goes away after 10-15mins drive time!!

Er, I doubt it. This is a standard optical encoder design. They are bog simple and very dependable.

Unless you are doing something silly like trying to spin the control so fast that you are exceeding the sampling rate. But that is a user defect, not equipment.

[Mike's ML]

Originally Posted by Bigburgundy

he doesnt have the 270 anymore. he has the 430...which he stated above...

Was the 430 sold in Europe and was the 270 sold in North America? He could still be in Europe and have the European version radio.
Mike

[Tarydesign]

Sorry all, I'm in SOUTH AFRICA, and yes I know its a digital volume control, thats what is even more strange!! Some of the cars I test drove (2 or 3 ?!?!?) had marks on the volume control where the user (without any knowledge) had tried to pull off the rubber knob to "fix" the problem.

What do the radio "keys" look like? - The ones to remove the radio?? We only had 2 versions of radio in this country that I am aware of, the standard and the Bose speakered system (With the sub under the left front seat). I think its an audio 10 or 20 or 30. With a 6 CD changer in the right hand rear panel.