bagwell

Its terrrible....In my C320 when listening to FM broadcast...and turning the rear defogger on...instant static. I brought in in for its first oil change and the service advisor said he'd never heard of such a thing....we'll see if they can fix it.

Carlos

Haven't noticed it, although I do tend to turn on the car and rear defroster go inside so usually the rear defroster is off by the time I get in the car. I'll try it and keep an eye on it.

Richard

The aerials are in the rear window, so theres some clever decoupling and amplification stuff to the sides of the rear window - if this is breaking, or there is oxide/contaminant buildup between the defogging elements and the aerial bits (tinting can do this) then static, particularly on AM reception can occur.

Richard

The FM/AM aerials are integrated into the rear windscreen. Theres a bunch of isolators/amplifiers in the panels beside the rear windscreen.

If these go wrong, or if contamination/oxidation gets on the inside of the windscreen between the aerial elements [yes, tinting can do this] then you can get inteference, particularly on AM reception.

Have you had your rear windscreen tinted ??

bagwell

there is no tint on the rear window...and I haven't even tried AM with the defogger on....I can only imagine how bad that would be...FM is bad enuf...I'll report back to see what the dealer says or does about it.

Richard

Hi, Mercedes have some Service Technical Info (STI) about this, its it service bulletin 82.60-036 (which can be found on their WIS system), basically looks like dodgy back windscreens on the earlier W203's to me ...

R

MB-BOB

...There were posts several months ago about rear windows being replaced to cure this problem. Your dealer may not have heard of it, but the problems does exist for a few. Hence the STI Richard refers to.

I have Bose and metallic tint on my rear window... no static, with or without rear defroster. To wake up your dealer, I'd tell them you've heard from several on this site about similar problems.

Nav

I had this exact problem. MB service had to install a new rear window because of the interference associated with the combined antenna and defroster electricals. It is done under warranty of course!

Richard

The STI 82.60-036 says vehicles with chassis nr up to xxxx1F038429 are affected by ground contacts covered in primer which just means replacing ground contacts, theres a further STI 82.60-041 which seems to say there are small cracks in the windscreen elements that spark across and cause the interference. The latter needs a new windscreen. Interestingly the latter STI replaces the first, which sort of suggests that the first STI didnt fix the problem , and the actual problem was dodgy windscreen manafacture.

Fuzzo

and my dealer replaced the rear window and all the amps/antenna (sp) in the rear to fix that.

I didn't have tint on the window when I discovered this but I did get the metallic tint on my car after this was taken care of it and it works just fine

MarkL

Richard, how were you able to find these service bulletins? This morning, I tried my rear defroster w/ the radio on (FM, non-Bose), and sure enough, there was static . My C240 was built in June 2001 (a 2002 model), and I'm surprised the problem is still occurring. I'm really hesitant about having my rear window replaced -- sometimes, they're never the same. At this point, I might just leave it alone.

bagwell

MarkL - my thoughts exactly - I don't know if I trust my dealer to replace the rear window. I bet the rear trim pieces won't be fitted correctly or they'll be scratches or.....well ya know.

Funny thing is when I was at the dealer - it worked perfect - I/we couldn't duplicate the problem. He even banged on the rear window internally and externally trying to get static...he was assuming the antenna assy (which supposedly is double stick taped to the back window.

Richard

Mark, I help a dealer with computer problems, so sometimes they let me look at their workshop info system ...

In the USA MB has to be much more open with non-MB dealers, so I assume the STI's would be available from MBUSA - for instance the proper service manuals arent available in Europe, so I ordered the eletrical diagrams from MBUSA last time I was in the USA and had them delivered to my hotel ;-) If you ask for technical publications when you phone the 1-800 number for MB they are very helpful.

I beleive you can even subscribe to the workshop information system (WIS) in the USA, although I doubt its cheap ..

Also, if the dealer removes any panels , tell them that you want them to replace all the clips with new ones - otherwise things always rattle

Cheers
R

pokerFACE

ok, somewhat different question..

I always put my cellphone in the little tray under the headunit and whenever it receives a call/SMS, my audio (radio and CD) gets garbled up. Isn't the sound system supposed to be fibreoptic??

bagwell

all cars I have driven do that with the cellphone....no exceptions....

.......Now why it does it ...I don't know.

MB-BOB

Regarding the replacement of rear windows. The last time this thread came up several weeks ago, the people who replied saying they had the windows replaced did not make any comments about the quality of the work done. i.e. they seemed to be happy with the work, or at least made no complaints. So, I wouldn't hesitate to have the dealer replace the window if that cures the problem.

Nav

You are correct MB-BOB, the quality of the repair from my dealership was excellent!

Richard

Mobile phones put out high(ish) power rf signals at around 1900Mhz, which will be interfering directly with the circuity in the COMAND/Audio-30 head unit. - in Europe, phones are basically universally GSM at 900 or 1800mhz, and if U leave them near normal telephones or any electronics they interfere with a "rut-a-tut-tut" noise quite regularly. I dont suppose the fact the the car is metal and the phone is inside helps , as the phones will be ramping up the power (and this eating up battery life) to find their base stations

Imagine what this does to your head ... theres lots of research being done here in Europe about that - and the UK goverment recooments kids shouldnt have mobiles (their skulls are thinner and it heats up more of their brains as a result)

Considering your domestic microwave is 2.4Ghz, and your phone is about 1-2Ghz - would you put your head anywhere near your microwave if you knew it was leaking 0.1% of its power ???

R

ChicagoC320

I just discovered that my 2001 has this problem (it didn't before). When I turn on the defroster I get static on my radio. I asked my dealer about the above STI but he couldn't find any reference and could not find a listing with this number.

Any updates?