I am having trouble with my Becker Grand Prix and want to replace it with an aftermarket radio. The problem is that one speaker always has a lot of static. If I swtich the wires on the back of the radio, the static moves to the other speaker which has me concluding that the problem is in the radio.

On the back of the Becker, there is a plug with 4 wires (Red, Black, Grey, and Tan). What are each of these wires for? Tan looks to be the ground.

There is also another wire that comes out from the radio and looks like it goes to the antenna switch. How does this wire unhook from the radio? I don't see a plug. Am I correct that the aftermarket radios will generally have an antenna power wire? Is this where I would connect that wire? I am looking at the Dual XD6425 and the bluetooth adapter

Thanks

83 380SL

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1983 380 SL
2005 GTO
1970 GTO
1969 Firebird

This really should be in the audio forum, but I'll throw a few thoughts your way, since no one has replied.
First of all, if you are looking at a new head unit, it will want new speakers as well, since the oldies in there that went with the Becker are 8ohm, and very bad quality by todays standards, and everything now is built for 4ohm.
I don't recall the old becker wiring, but I did note the wires and wrote down what went where when I removed mine about 10 years ago. I could look it up, but to make this conversion easier, first get your new unit and speakers, then you can get into the 2 wiring projects that are involved: speakers, and power/ground/antenna trigger.
Read up on the subject matter discussed in the audio forum. The SL speakers are straight forward, there's only 2 and the wires are + and -. All you need do is follow the instructions for hook up that will accompany your new receiver/player or whatever you pick. I'm guessing the 4 wire plug will lead to each of these speakers.
You can use a multimeter, or any 12V light, to find the switched power wire into the Becker. Ground is obvious, always a brown wire, maybe with a stripe.
The antenna trigger is a bit of a 'kettle of fish'. Again, do some reading first. If your antenna is original, and works well, and you want to retain the dash switch functionality, you're in for some real fun. If you just want to use the antenna without the switch, or have a later aftermarket....well, let's just get going and see where it goes.

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1986 560SL
2002 Toyota Camry
1993 Lexus

(follow up from PM received from another member, who wants to replace his aftermarket with a Becker. This info might be of some value to both members)

First pic is a scanned image of notes I made for the plug on the back of the Becker, I think..... it was years ago. One is a sketch of the radio female plug input, the other should be the harness male plug (or could be the wiring to the aftermarket unit?). Second is the back of the radio, showing the female plug and the 2 speaker plugs.

This was from my 1985 380SE. No idea what the SL wiring was like, as my SL had already been converted to an Alpine. I did put a Blaupunkt in the SL, which I got off EBay, very fortunately from a fellow who had installed it in his Mercedes, so all the wiring was 1/2 done for me!

For the OP's benefit, just remember that 99% of aftermarket radios need 1 constant 12V source (for the memory), 1 switched 12V source (main power), a trigger wire for the antenna (usually blue), and sometimes a third 12V source from the circuit that powers the dashlights (most people just let the switched 12V source power up the unit and the illumination at the same time.

Attached Thumbnails

   

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1986 560SL
2002 Toyota Camry
1993 Lexus

Thanks Don!!!!!!!

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Birmingham, AL
2006 Audi A4 "Audrey"-daily driver
1976 MB 450SL "Marlene"
2000 Jetta VR6 "Julia"-traded at 220k miles
1997 Jetta 2.0Trek "Blanche"-traded at 450k miles YES 450,000 miles
1986 Prelude "Gladys"-died at 120K miles

Thanks, I appreciate this. Wish I could get my Becker to work without sending it out. I always get static from the left speaker. If I switch the speaker wires are the radio, then the static moves to the right speaker. I'm sure then the problem must be in the radio. Maybe I'll open it to see if there is somewhere I can use TV tuner cleaner.

The wiring diagrams are much appreciated.

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1983 380 SL
2005 GTO
1970 GTO
1969 Firebird

I have heard that hooking up the speaker wires backward is not a problem as long as you hook them ALL up that way. Do you know if this is correct?

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

^^I understand this also, yet the speaker will be pushing in the opposite direction if you get them crossed up. As in, instead of pulsing up, it will pulse down.
Does anyone know what color wires in a SD front and rear speakers are positive and negative?

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83 SD

84 CD

Take an AA or AAA battery and connect the speaker wires to the + and - ends/terminals. The speaker cone will move either in or out. IIRC, you want the cone to move out and this will be the + and - wires corresponding to the battery terminals. And yes, I believe this is correct, as long as the cones all move in unison.

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1986 560SL
2002 Toyota Camry
1993 Lexus