I just replaced the battery in my 1999 C280 Sport and all is working fine. The only issue is I can't get the radio to even turn on so I can enter the radio code. I followed the instructions in the MB manual which says to turn the key to Position 1 and look for a readout.

I have turned the key to both Position 1 and 2 and the radio will still not show a blip. I've pressed the "On" button and even held it for a prolonged period of time and nothing comes on the display. Any help is appreciated.

Also - I noticed when I took the old battery out (it was an MB battery) that there was a little clear hose coming from the bottom of the vehicle and seemed to be plugged into the old battery. The hose ends with an L shaped plastic nipple which looked like it was plugged into the battery. The new battery has the same open spot for the nipple but not enough room to slip the hose in to - any ideas on that would be appreciated as well.

1999 C280 Sport - VIN: WDBHA29G1XA707073

 

Check for blown fuses.

 

breather pipe. it will prevent the acid inside the car.

 

on some model radios there is actually a fuse located behind the radio- check and replace if necessary-- i hope you have the tool to pull radio though-

 

Re: L shaped hose

So I should have it plugged into the battery in some way? If so, how do I compensate for the new battery having an opening the size of a flat head screwdriver tip and the hose being a mini circle?

 

Hi
From an Mercedes Benz advising expert who is my friend. I have told that the way MB designs to work with its own Battery. Therefore, the size and location of the most electrical parts are specially designed for MB cars. I have passed thru this experience on my 2000 E320. I believed that between 1999 up to now models, in order to replace your battery, you need to bring to an authorized MB dealer for them to appropriate replace it because they has special tools to reset all the memory included the radio code( I can't provide in detail base on our company secret). About the price, it i scost about $150.00 in my place. Compareing to do it yourself to save money, I think, it save your headache and time which is valuable unless you really know what are you doing. I believed that the MB intended to design this way. I have heard a lot of complains about it and that is the latest news I found out from My friend as I mentioned earlier who is also a Design Engineer for his company who participated in the designed electrical parts for MB. I am a Support CAD Engineer to relate to many MB Desined Projects and other automobiles so I wamt to share it with you (As long as it is permitted by law). I am also a current law student so I must obey the law and not leak company secrets but I can give you some hints. Who think that more expert than me and don't believe what I said then you will fee free to share with me but pleae don't criticize since I am a professional in this industry. I don't know how to fix car like you guys but I am working and assist design Engineers and I am also an Engineer so I share wihch what I know.

Regards,
Joseph

 

Yeah, do all that hoop dancing... or just buy a sealed, maintenance-free battery.

The new battery should have come with a length of drain hose. Go back to where you bought it and ask. Otherwise, go to an auto parts store, better yet a battery store, and ask for one.

 

The battery is a sealed maintenance free model, so that issue is solved - thanks for your help.

The radio issue has been checked into. The fuses (3/10 according to the fuse diagram) are solid and intact. I was told by a stereo shop that I should check all the fuses in there because it is possible that some other electrical system in the car (windows, temperature cluster, etc) is linked to the radio and if that is out - the two could be linked - so check all the fuses. He also said that it is possible the radio "shorted" out. The reply that said it was specific to MB batteries was incorrect. To prove the theory, I put the old battery from MB back in and the radio was still not showing any signs of life, while all other elctrical components were fine. There is also no fuse behind the radio.

The issue now is, it has to be taken out (the radio) of the dash to ensure all the connections work - if they do (and it can be tested by amp and voltage meters) then it must be the radio unit and it would need to be replaced.

Any thoughts on this probelm are greatly appreciated. My next move is to pay the shop to pull the radio, but I'm hoping that won't be necessary.

 

Hi My Friend
You may said that I am incorrect but you didn't mentioned clearly that your radio has gone before or after your battery has been replaced. However, once you have disconnected everything from battery and reconnect, you need a proper reset and only dealer has that tool to test your battery and your car system. It is called "MIDTRONICS TEST". I have just replaced my battery which is required to do so every 3 years. It is expensive, yes. But you must realize one thing, if you can buy a Benz, everyone consider you has money so the quality of the MB may not be different from a SEAR battery but it has been modified to work with all electrical components in the car. If you are a Programmer, you must know Java Program will give you no excuse if you execute a wrong statement. The design on Benz electrical system was the same since the hi-Tech is more and more complicated. MB is intended to design their car that way. If you think that I am incorrect, you can continue to pursuit that way to maintenance your car and you will continue has more headache. I think your stereo need to be replaced since it was short due to many reasons cause by improper power input, microprocessor reset incorrectly,, etc. Of course, once you made a first mistake with wrong battery type which cause the shortage, then you even put an OEM battery back after, it will not help. My car has just replaced a new battery from Dealer so I want to share with you the true. If your car is back to earlier years like my first Benz, 1993 190E, you probably can do the battery replacement quite simple but since the elctrical design for MB automobiles is more sophisticated, the power source replacement for the whole car is no longer that simple as you thought. I suggest you come to any Mb to get it fix with the new radio than just stuck around with so much headache. Believe me, time is golden and you need to make money too. Don't waste your time for this little thing. $125.00 for battery replacement and computer full reset is not a big buck compare to the problem you have right now. YOU CAN IGNORE THIS STATEMENT AND MAY BE I AM JUST HAVE A BIG MOUTH BUT I REALLY WANT TO HELP YOU OUT.

Regards,
Joseph

 

What a load of bull poop.

The dealer's "special tool" for resetting the ECU is a scan tool. My special tool is disconnecting the battery cables. It does the same thing.

The radio code is included in the owner's papers along with instructions in the owner's manual on how to reset the radio.

These aren't company secrets, for chrissake.