Hello I am having a problem to get my stock Becker radio to play in my 85 300sd. I used to have a sony XR-5600 that played pretty well and got a lot of stations but it went bad so I got a stock Becker at a salvage yard to put in. I had a replacement power antenna in but it was broke and no longer went up and down so I wanted to replace with a fixed antenna I did have to get an adapter to go from the fixed antenna end to my antenna wire coming from tne front and so far I have tried 2 fixed antennas and 1 hidden antenna and can get no reception with none of them. Today I put the old broken antenna on in the garage and was getting fairlygood reception went out for a ride and got hardly nothing but a lot of static. Also ever since I put this Becker radio in every time I start the car I hear a crack in the speaker if I turn the radio off while driving I cannot turn it back on will only go back on if I shut the vehicle down and restart. I am pretty sure I have it wired right in that there are 4 wires off the back brown is ground,next switch + blk+y wire, illum.+ grey and violet wire, constant + red wire. I am at my wits end in getting this thing to play does any have any ideas as to where my problem lies? Some one told me to go to Best Buy and let them install a new radio and it will have to work but I do'nt think I would want to spend more then $100 to get this thing to play. Also if I hit the seek button it never stops on a station must keeps seeking and if I do have a station on where it is stereo reception and shut the car off the red stereo stays lit so before I shut it down I have to switch to a station that is not stereo.

I found my biggest problem with the poor reception on my Becker grand prix 612 was the metra 40VW-16 adapter to mount the fixed antenna was not fitting properly and would not let signal thru seems like it will be much better now getting 6-8 stations fairly clear. I will know better when I drive it. The radio still has some strange quirks when you first start vehicle you hear a pop in the speaker, if I shut radio off while driving I cannot restart it w/o shutting vehicle off and restarting, and I cannot shut vehicle off with the little red stereo light on as it will stay on and be a battery drain, and last the cassette player at first played my adapter cassette with my I-pod very clear but the cassette was very noisy while revloving,and last but not least AM reception is not as good as FM. When I called Becker about refurbishing they quoted me a $175 price the radio is no where near worth that in perfect working condition. I have 3 choices:
1.Use it the way it is.
2.Buy a much better new radio with front usb i-pod inputs.
3. If someone has a Becker 612 in good working condition I would be interested in it.

yuk you can try this .It will come in for other jobs you do on your W124 ,, on google search put in MERCEDES BENZ MODEL 124- MAINTENANCE MANUALS. Dont leave out the - after W124. I found the radio section but its not the same number as yours but wiring may be the same . on number 82 on the page. This is for the w124 not w123 i was not sure of your car.