When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
00 MB ML55, 91 Toyota Supra Turbo(sold), 06 E500(gone), 03 BMW M3
03 SL55 Radio Install
I have combed through a bunch of the existing threads on the topic and I think I have a solid understanding on installing an Aftermarket radio in the R230 chassis.
03 and prior use MB specific fiber adapter which has no aftermarket support - EVERYTHING must be rewired
04 and after use industry standard adapter, and aftermarket radio can be integrated but you lose control of F/R sound stage.
My question, if I install an aftermarket radio and I bypass the factory amp, can I integrate an aftermarket amp, and wire it up to the Bose speakers? I know sometimes that Bose runs individual amps in the crossovers but unclear of what the early SL set ups are like? Is the sub reusable? or do I need to install my own?
I have combed through a bunch of the existing threads on the topic and I think I have a solid understanding on installing an Aftermarket radio in the R230 chassis.
03 and prior use MB specific fiber adapter which has no aftermarket support - EVERYTHING must be rewired
04 and after use industry standard adapter, and aftermarket radio can be integrated but you lose control of F/R sound stage.
My question, if I install an aftermarket radio and I bypass the factory amp, can I integrate an aftermarket amp, and wire it up to the Bose speakers? I know sometimes that Bose runs individual amps in the crossovers but unclear of what the early SL set ups are like? Is the sub reusable? or do I need to install my own?
I have combed through a bunch of the existing threads on the topic and I think I have a solid understanding on installing an Aftermarket radio in the R230 chassis.
03 and prior use MB specific fiber adapter which has no aftermarket support - EVERYTHING must be rewired
04 and after use industry standard adapter, and aftermarket radio can be integrated but you lose control of F/R sound stage.
My question, if I install an aftermarket radio and I bypass the factory amp, can I integrate an aftermarket amp, and wire it up to the Bose speakers? I know sometimes that Bose runs individual amps in the crossovers but unclear of what the early SL set ups are like? Is the sub reusable? or do I need to install my own?
Anyone DIY something like this before?
If you listen to AM radio (most folks don't anymore, I suppose), you will find that with your new head unit you will have near zero AM reception with the top closed (and normal reception with the top in the trunk). This is because the factory head unit (2003 and 2004 r230) and the audio gateway (2005 and later R230) provide a control signal (that is based on a CAN signal the HU or audio gateway gets from the top controller,N52) to the rear AM antenna switch/amp (A2/67) which in turn, sources the am antenna from the rear deck or rear window depending on top position - but now with your new head unit, your antenna switch will ALWAYS think the top is in the trunk (and use the rear deck antenna ONLY).
Worth mentioning ....
The wiring diagram on Mercedes ETM shows that a "top closed" switch (S69/1) provides the needed top-status signal DIRECTLY to A2/67 ... but this is not the case. Contrary to the Mercedes wiring diagram (but consistent with Mercedes' block diagram disambiguation), the top status comes from N52 (unrelated to the actual status of switch S69/1)as a CAN signal to the factory head unit on 2003-2004 R230s (and to the N93/1 "audio gateway" on 2005+ models) where it is translated into voltage coding.
There is a work around I created if AM radio is important to you.
On my 2003 R230, I used a nice Alpine AMP to power the (4) door speakers and sub .. I used all of the factory speakers (EXCEPT the sub which I replaced). Then, running off of the "speaker outputs" of the new (kenwood DMX906s) I wired the front center speaker as "center channel" and rewired the rear fill speakers as left and right (later I went back and added a resistor in series with each of these "speaker outputs" to aid in some gross signal level balancing of the speaker outputs of the head unit vs the alpine amp (I can get the specific values I settled on if anyone is interested).
If you listen to AM radio (most folks don't anymore, I suppose), you will find that with your new head unit you will have near zero AM reception with the top closed (and normal reception with the top in the trunk). This is because the factory head unit (2003 and 2004 r230) and the audio gateway (2005 and later R230) provide a control signal (that is based on a CAN signal the HU or audio gateway gets from the top controller,N52) to the rear AM antenna switch/amp (A2/67) which in turn, sources the am antenna from the rear deck or rear window depending on top position - but now with your new head unit, your antenna switch will ALWAYS think the top is in the trunk (and use the rear deck antenna ONLY).
Worth mentioning ....
The wiring diagram on Mercedes ETM shows that a "top closed" switch (S69/1) provides the needed top-status signal DIRECTLY to A2/67 ... but this is not the case. Contrary to the Mercedes wiring diagram (but consistent with Mercedes' block diagram disambiguation), the top status comes from N52 (unrelated to the actual status of switch S69/1)as a CAN signal to the factory head unit on 2003-2004 R230s (and to the N93/1 "audio gateway" on 2005+ models) where it is translated into voltage coding.
There is a work around I created if AM radio is important to you.
On my 2003 R230, I used a nice Alpine AMP to power the (4) door speakers and sub .. I used all of the factory speakers (EXCEPT the sub which I replaced). Then, running off of the "speaker outputs" of the new (kenwood DMX906s) I wired the front center speaker as "center channel" and rewired the rear fill speakers as left and right (later I went back and added a resistor in series with each of these "speaker outputs" to aid in some gross signal level balancing of the speaker outputs of the head unit vs the alpine amp (I can get the specific values I settled on if anyone is interested).
There is a work around I created if AM radio is important to you.
Old post I know but what is the workaround??
I was going to buy a used A2/67 and see if maybe it has a relay inside that switches the outputs.
I could maybe then rig up a button or something to manually activate the relay. Or actually wire S69/1 over to the antenna/amp
If you already have a solution, I'd love to hear it!!!
Last edited by marko69; Feb 10, 2025 at 10:26 PM.
Reason: added a sentance
Old post I know but what is the workaround??
I was going to buy a used A2/67 and see if maybe it has a relay inside that switches the outputs.
I could maybe then rig up a button or something to manually activate the relay. Or actually wire S69/1 over to the antenna/amp
If you already have a solution, I'd love to hear it!!!
I have some notes and pictures somewhere that I can dig up. It's been a long time since I did this on my car but it was really basic and it was fully automatic once installed and solved the problem.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
