'95 E320 Radio Volume Control .... weird - PeachParts Mercedes-Benz Forum

haasman · #1 11-05-2002, 02:13 AM

Has anyone run into this one:

Our '95 E320 Radio Volume Control is .... weird. In warmer weather it operates just fine. but with the weather getting cooler, in the mornings, I can turn and turn (fact. radio with the round volume knob) and it either doesn't affect the volume or as I turn it clockwise the sound level goes down!

This is true for both AM/FM and CD. Any ideas? Any DIYer solutions?

haasman · #2 11-06-2002, 12:16 AM

anybody?

SCLJA · #3 11-06-2002, 12:27 AM

Check with Cleeve @ www.lajollaaudiorepair.com and he can help you!

Scott

Limited Edition · #4 11-06-2002, 12:29 AM

That happens alot with those stereos.

You may be able to fix it yourself by taking off the faceplate and lubricating the volume gear.

Regards,

Don

haasman · #5 11-06-2002, 12:26 PM

Don,

Thanks for the tip. Could you explain a bit more about doing this. Have you had to do it yourself?

Where is the best place to lube it? I resume after removing the radio, I take the cover off it as well? Finally, what kind of lube? WD40 ...

Haasman

ahobgood · #6 11-06-2002, 04:28 PM

I had a similar problem with my E320 which I just tolerated.

Then, the AM/FM switch stopped working (if I switched to CD, for example, it wouldn't switch back to AM/FM.

Coincidenatlly, I had to take the car to my shop for something else the next day, and I mentioned it.

When I picked it up there was a line item (N/C)...lubricated radio switches and it is fine now.

How lubrication fixed it is a mystery to me...switch sounded as if it was working (got the normal "click".

haasman · #7 11-06-2002, 04:32 PM

The mystery continues! I like a quick and easy solution. Does one just spray silicone into the face?

SCLJA · #8 11-06-2002, 11:49 PM

This is not a fix, it will only cause problems with this model radio and I guarantee it will make a mess of things. The pot needs replacing.

Scott@lajollaaudio

Kestas · #9 11-13-2002, 06:54 PM

My car does it too. I'm gonna try cleaning the pot. I'll post the results when I get around to it.

haasman · #10 11-13-2002, 06:56 PM

Kestas Let me know how you do it and how it goes.

Haasman

Yury · #11 11-24-2002, 10:02 PM

I think this is know issue with these decks, it acts up sometimes when I turn the volume down it makes it louder. By turning the volume knob slowly it works fine everytime, I can live with it

Yury

Kestas · #12 11-25-2002, 10:48 AM

I've run into this problem on other radios. I've taken apart the pot and cleaned it on my MB radio. It's not easy to do, since the pot is so small on this radio. I think that because of its small size, that it's more sensitive to dirt.

I have the luxury of having steroebinoculars and an ultrasonic cleaner at my disposal. Once the pot was apart, I cleaned the metal surfaces with an eraser. An eraser is typically formulated with abrasives and does an excellent job cleaning electrical contacts. (I've restored a number of old Philco tube console radios this way.) I couldn't flood the contact with solvent... the contacts are sealed. After cleaning with the eraser, I ultrasonically cleaned eraser residue from the pot.

The contacts could be contaminated in a number of ways. One is from the plastic on the toothed wheel that holds the detent. The other is from the shaft bore (mine was very dirty). This radio was in a very dusty environment. When I took the radio out of the dashboard, the cavity was packed with lint.

I'm not sure if this operation has cleared up the problem. I'm doing a lot of other work concurrently on the car, and it'll be some time before I hook up the battery. I'll let you know how things turn out.

BTW, I made the keys to remove my radio, thus saving myself about $13.

#13 11-27-2002, 08:10 PM

I've noticed a similar problem with my head unit ('95 E-320). If I turn the volume knob too quickly, nothing happens, almost as if moving too fast for the contacts to meet properly. Immediately afterward, if I turn the knob more slowly the volume works just fine.

I also thought that the bass control didn't work for the first couple months of owning the car. My brother, a former Mercedes mechanic, also couldn't seem to get the bass control to work. I eventually discovered that even if I felt the "click" while pressing the button, it didn't actually contact unless I gave it A LOT of pressure. Problem solved.

Hope this helps, if it applied to your problem.

Cleeve · #14 11-28-2002, 04:21 AM

To Everyone,

The main head units used in the 95's is either Becker or Alpine OEM unit. These both use HEX (electronic) vol. controls, thus the fact that the knobs can be turned with no stopping point like the old analog type. These controls are sealed types and have no ability to be lubed and infact if you were able to get lube inside them you would compound the problem even more so. The control inside is a dry control to do what it needs to and if anything is sprayed or put into it, falsing will occur to the CPU inside that controls the vol. level and so when you turn it maybe it will respond or maybe not. If you turn a normally functioning control too fast you can cause it to miss some of the data being transmitted by it to the CPU and so causing it to remain at the last level it was at. Temperature can affect it due to moisture that can get inside a failing control.
The solution: get the control replaced which we do all the time.
Visit our Web site: www.lajollaaudiorepair.com

Cleeve Morrison
La Jolla Audio Repair

Yury · #15 12-01-2002, 04:39 PM

Cleeve,
why get it replaced if it works fine by turning the knob slowly???

Yury