Sub wiring for W212 with Logic7
Thread Starter
Member
Joined: Jul 2012
Posts: 165
Likes: 1
2010 E350
Sub wiring for W212 with Logic7
I installed a box in my W212 last night. The lack of information is frightening with respect to wiring etc. It's a quick DIY and the results are phenomenal.
This will work with any amp that has high level inputs. First locate the panel covering the fuses on the right side of the trunk and remove it. Route the power wire under the trunk floor trim and into the fusebox area. I used a blade connector and just chose an open relay slot with power, it's the red wire in the bottom of the photo, see image:
Next run the ground wire over to the ground distribution stud to the left of the fusebox. Use a round lug on the ground wire and tighten the nut snugly, see image:
For switched power I tapped into the aux power port just behind the fuse box. I used a tap and a blade to grab switched power, see image:
Last but not least you'll need some sort of signal from the sound system. There is a fan under the rear deck located on the driver side. Remove the plug that inserts into it and locate the brown/green and green, OR brown/blue and blue wires. Once again I used taps and blade connectors to get signal. The wiring harness is very short so I was only able to tap one side for signal. My boombox had a set of wires for the other channel but there isn't enough room for them. Ultimately it is best to make an adapter from a male and female connector as a break out box sort of setup but this works just fine, see image:
Voila - you've got a nice addition to your Logic 7 system.
This will work with any amp that has high level inputs. First locate the panel covering the fuses on the right side of the trunk and remove it. Route the power wire under the trunk floor trim and into the fusebox area. I used a blade connector and just chose an open relay slot with power, it's the red wire in the bottom of the photo, see image:
Next run the ground wire over to the ground distribution stud to the left of the fusebox. Use a round lug on the ground wire and tighten the nut snugly, see image:
For switched power I tapped into the aux power port just behind the fuse box. I used a tap and a blade to grab switched power, see image:
Last but not least you'll need some sort of signal from the sound system. There is a fan under the rear deck located on the driver side. Remove the plug that inserts into it and locate the brown/green and green, OR brown/blue and blue wires. Once again I used taps and blade connectors to get signal. The wiring harness is very short so I was only able to tap one side for signal. My boombox had a set of wires for the other channel but there isn't enough room for them. Ultimately it is best to make an adapter from a male and female connector as a break out box sort of setup but this works just fine, see image:
Voila - you've got a nice addition to your Logic 7 system.
Last edited by norcal_cyclist; Aug 30, 2012 at 01:51 AM.
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Senior Member
Joined: May 2007
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asdas
Great job with the pics and figuring this stuff out on your own. I'm about done with mine except I need to route power wire directly from the battery. I did some investigating of that fuse panel and it seems the power wire going to it isn't a very heavy gauge. I'm afraid a small wire coming out of that fuse panel won't suffice for my 800 RMS watt amp.
Did tapping into the signal going into the stock sub amp change the sound or output from the stock sub?
Did tapping into the signal going into the stock sub amp change the sound or output from the stock sub?
Thread Starter
Member
Joined: Jul 2012
Posts: 165
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2010 E350
I think mine is a Kicker PT10.. at 100watts RMS I felt I was good to go. Running a power wire from the front of the car does not appeal to me at all 
1 plug and 2 velcro straps I have my entire trunk back
1 plug and 2 velcro straps I have my entire trunk back
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Joined: Sep 2006
Posts: 761
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From: Oklahoma
W211 E320 & W212 E550
Let me offer some advice here. I think you've done some good stuff, good idea's for some bump but you have overlooked some important key things with this install. Your power source concerns me most and maybe I don't have the full picture. Although I would never run a power wire of that magnitude through a stock fuse block. If I did I would surely have a fuse placed immediately right after the tap. I want you as well as everyone here to know that eventhough something is fused correctly, a too small wire can generate heat, melt down and burn your car before it ever blows. Same thing with the fuse block itself because it is a factory low amperage unit. It is made of plastic and generally arent made for the constant current a sub amp can pull. There should be a battery by the spare tire in the trunk, it may just be the 550's im unsure. But if there is a battery in the trunk, you need to run your power and ground straight to it. Immediatly fuse it at the battery. If you do not have a battery in the trunk, then I would run it to the front. Now if there is a way to tap power off a large gauge wire or connection before the fuse block, then that's what would be a good power source as well. Anyway take my advice seriously, done this stuff too many years and melted a block into a charred mess back in my younger days doing the same thing. Luckily no fire but close.
On a side note, looks like you have a kicker amp cause I see the bass control knob. Those are fantastic units as I have a kicker amp in my Honda Civic daily driver. Also how does the bass sound through the seat and back deck? Does it add some good bass?
On a side note, looks like you have a kicker amp cause I see the bass control knob. Those are fantastic units as I have a kicker amp in my Honda Civic daily driver. Also how does the bass sound through the seat and back deck? Does it add some good bass?
Thread Starter
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Joined: Jul 2012
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2010 E350
RNBRAD: Thanks for the information.. however the wire I used was supplied with the Kicker box and is more than adequate as the amp is a mere 100 watts RMS and protected with a 15amp fuse
Unfortunately my battery is under the hood so that option was not a good one for me. The fuse box and associated wiring will be just fine but you do make a good point... anything more powerful than what I have needs a better power supply. There are some very large wires behind the box but I cringe at the thought of tapping one of those.
Once I got the phase correct I had to turn it down. It adds just the right amount of low end for me. I think it'll be perfect once I get done playing with the crossover point and gain.
My E30M3 has a high end setup and luckily the battery is in the trunk so I ran power and ground wires directly to the battery. As for my experience and qualifications... 35 years in the business on and off, a degree in electronics and never had a single meltdown, knock on wood!
Unfortunately my battery is under the hood so that option was not a good one for me. The fuse box and associated wiring will be just fine but you do make a good point... anything more powerful than what I have needs a better power supply. There are some very large wires behind the box but I cringe at the thought of tapping one of those.
Once I got the phase correct I had to turn it down. It adds just the right amount of low end for me. I think it'll be perfect once I get done playing with the crossover point and gain.
My E30M3 has a high end setup and luckily the battery is in the trunk so I ran power and ground wires directly to the battery. As for my experience and qualifications... 35 years in the business on and off, a degree in electronics and never had a single meltdown, knock on wood!
Super Member
Joined: Sep 2006
Posts: 761
Likes: 23
From: Oklahoma
W211 E320 & W212 E550
Let me put it in a different scenario. I wasn't so much worried about your amp wiring as I am the OEM block itself. You just never know what the circuit is rated for and the resistance burden it may place on "shared" power sources even when things are running as expected. Most people look at it as, "well it's a small amp it doesn't draw much power". However correct that may be, you should always install an amp based on a worst case scenario as if the amp was to fail and create a circuit, could that OEM block handle the load till the fuse blows? Are you willing to risk your car, home, and possibly your life on it? Your chances may be small, but a proper install could make the chance impossible. Make sense?
Anyway good stuff, I do appreciate you sharing this info. My electronic background is car audio specific and this is why I get so vocal about it . I've been a top competition level installer, (sq/install)judge, and competitor for many many years, though I retired from it full time in 2001. I still do it as a hobby though cause I still love it so much.
Anyway good stuff, I do appreciate you sharing this info. My electronic background is car audio specific and this is why I get so vocal about it . I've been a top competition level installer, (sq/install)judge, and competitor for many many years, though I retired from it full time in 2001. I still do it as a hobby though cause I still love it so much.
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From: PA
18'Porsche GT3, 16' Ram 3500 mega diesel,30' Model A Ratrod, 17' E43
RNBRAD, have you done anything to your 550? Also, I think only the 550's have the 2nd battery in the trunk for the airmatic, wondering if it would be ok to use as a power source with a proper fuse?
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asdas
Is there anything different about the smaller fuse locations that hold a 30 amp fuse vs 5 or 7 amps? If not, I think it would be safe to use the one he did with a 15 amp fuse on it as long as the wire gauge is sufficient.
I however have seen "add-a-circuits" melt at well below 15 amps. Some of those can be very unsafe.
I however have seen "add-a-circuits" melt at well below 15 amps. Some of those can be very unsafe.
Thread Starter
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Joined: Jul 2012
Posts: 165
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2010 E350
The spot I used is for a missing relay.. relays route high amp circuits. I figured I was safe using this spot. If you look at some of the fuses / circuit breakers, they're as high as 50 amps!! yikes
Super Member
Joined: Sep 2006
Posts: 761
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From: Oklahoma
W211 E320 & W212 E550
Rob, haven't done anything yet. I've scoped it out and that battery location and size would be perfect. Would be a relatively easy install unless I get all crazy, which I probably will. I need to keep it simple though cause I want to maintain the use of my trunk.
brauhaus, that is the key, there is a difference between low amperage circuits and higher amperage ones in fuse blocks. Terminal contact are bigger along with larger wiring in and out. The contact points within the fuse block, if not designed to handle the load, can get very hot to the point of burning the surrounding case. The fuse will never even come close to burning, it puzzles many people but you will easily burn your car to the ground and the fuse will be good as new.
Even with all things perfect, I've melted the internal solder of a 60 amp agu glass fuse just from constant current. I would eventaully lose power to my amp and I would look at the fuse and the filament would be fine other than it may drop on one end. The fuse would actually get that hot and the pinch connector was attached to plastic. It deformed the plastic. It can get that hot and never blow the fuse. So I created 2 circuits with 2 60 amp agu fuses and ran the same amp draw split through 2 fuses. Solved the problem!!
brauhaus, that is the key, there is a difference between low amperage circuits and higher amperage ones in fuse blocks. Terminal contact are bigger along with larger wiring in and out. The contact points within the fuse block, if not designed to handle the load, can get very hot to the point of burning the surrounding case. The fuse will never even come close to burning, it puzzles many people but you will easily burn your car to the ground and the fuse will be good as new.
Even with all things perfect, I've melted the internal solder of a 60 amp agu glass fuse just from constant current. I would eventaully lose power to my amp and I would look at the fuse and the filament would be fine other than it may drop on one end. The fuse would actually get that hot and the pinch connector was attached to plastic. It deformed the plastic. It can get that hot and never blow the fuse. So I created 2 circuits with 2 60 amp agu fuses and ran the same amp draw split through 2 fuses. Solved the problem!!
Super Member
Joined: Sep 2006
Posts: 761
Likes: 23
From: Oklahoma
W211 E320 & W212 E550
For "switched power" is that switched with the car or the stereo? I'm assuming car as an auxillary with stereo would be unlikely but sure would ike one. Also I think with the Kicker amps, they have turn on sensing through high level inputs. Don't think the switched power is needed for turn on signal. Anyway fixing to put in an 1100 watt alpine and a 15" sub. Still haven't decided on the sub, maybe a Kicker L7 or maybe an Image Dynamics IDQ15. Decisions decisions.
Senior Member
Joined: Jan 2015
Posts: 345
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2011 AMG E63
I'm going to do a powered sub too in the back, I'm going to need to hit the fuse box for power as well, I looked at the fuse box for sale on ebay and there are definately big enough wires coming out to support a 100 watt amp, but some are much larger than others, does anyone know a definative good spot to tap on the fuse box that definately is 30 amp rated?
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Joined: Mar 2015
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w212
RNBRAD has a point, man. Good going on the install, BTW. But not only is that 'fuse block' a fuse block; it is also the rear SAM. This is a control module for some of the body electronics. If it melts or has an internal fault the thing is close to a grand to replace. If you feel confident, by all means.. I personally would not stick a spade into any open relay terminals and try to power something with it. Not even an LED. If for some reason that connection has any resistance it will heat up. (Amperage will rise with resistance). If i can remember, tomorrow, I will take a look at some schematics at work and see if there is a good power source back there for ya. Otherwise I too recommend running an independent circuit from the battery.
By the way, If a benz has a second full size battery its used to separate the starting circuit from the rest of the car. Benz hasnt done this in a while, tho. The battery for the starter will be in the engine bay and the 'main' battery will be in the trunk. There is also a small battery used to power the EIS.
Anyways, Ill see what i can dig up for ya tomorrow. Id hate to see ya damage that rear SAM. Its big bucks, man.
By the way, If a benz has a second full size battery its used to separate the starting circuit from the rest of the car. Benz hasnt done this in a while, tho. The battery for the starter will be in the engine bay and the 'main' battery will be in the trunk. There is also a small battery used to power the EIS.
Anyways, Ill see what i can dig up for ya tomorrow. Id hate to see ya damage that rear SAM. Its big bucks, man.
Junior Member
Joined: Mar 2015
Posts: 51
Likes: 1
w212
RNBRAD has a point, man. Good going on the install, BTW. But not only is that 'fuse block' a fuse block; it is also the rear SAM. This is a control module for some of the body electronics. If it melts or has an internal fault the thing is close to a grand to replace. If you feel confident, by all means.. I personally would not stick a spade into any open relay terminals and try to power something with it. Not even an LED. If for some reason that connection has any resistance it will heat up. (Amperage will rise with resistance). If i can remember, tomorrow, I will take a look at some schematics at work and see if there is a good power source back there for ya. Otherwise I too recommend running an independent circuit from the battery.
By the way, If a benz has a second full size battery its used to separate the starting circuit from the rest of the car. Benz hasnt done this in a while, tho. The battery for the starter will be in the engine bay and the 'main' battery will be in the trunk. There is also a small battery used to power the EIS.
Anyways, Ill see what i can dig up for ya tomorrow. Id hate to see ya damage that rear SAM. Its big bucks, man.
By the way, If a benz has a second full size battery its used to separate the starting circuit from the rest of the car. Benz hasnt done this in a while, tho. The battery for the starter will be in the engine bay and the 'main' battery will be in the trunk. There is also a small battery used to power the EIS.
Anyways, Ill see what i can dig up for ya tomorrow. Id hate to see ya damage that rear SAM. Its big bucks, man.
Senior Member
Joined: Jan 2015
Posts: 345
Likes: 3
2011 AMG E63
The original poster is long gone, but I'm doing this soon so any advice would be appreciated. As I said there are at least 3 large wires coming out the back of this thing, I was hoping to find a lug to one of the large ones on the back, but no dice, they all plug into the box. I just want some bass at this stage of the game and no way I'm ripping up the car to do it, been there, done that too many times already. Just want a good spot I can pull 15 amps from and probably less depending on the sub. Its basically down to
http://www.crutchfield.com/p_777B8P/...8P.html?tp=114
This one has a 7.5 amp fuse and the wattage is less than the OP used.
http://www.crutchfield.com/p_109GTPR...12.html?tp=114
This one the manual says 13.5 amps max and uses a 25 amp fuse on the box and says to fuse with a 20 amp on the power lead.
I'd like to relive my youth with the JBL, but if it can't happen, it can't happen.
http://www.crutchfield.com/p_777B8P/...8P.html?tp=114
This one has a 7.5 amp fuse and the wattage is less than the OP used.
http://www.crutchfield.com/p_109GTPR...12.html?tp=114
This one the manual says 13.5 amps max and uses a 25 amp fuse on the box and says to fuse with a 20 amp on the power lead.
I'd like to relive my youth with the JBL, but if it can't happen, it can't happen.
RNBRAD has a point, man. Good going on the install, BTW. But not only is that 'fuse block' a fuse block; it is also the rear SAM. This is a control module for some of the body electronics. If it melts or has an internal fault the thing is close to a grand to replace. If you feel confident, by all means.. I personally would not stick a spade into any open relay terminals and try to power something with it. Not even an LED. If for some reason that connection has any resistance it will heat up. (Amperage will rise with resistance). If i can remember, tomorrow, I will take a look at some schematics at work and see if there is a good power source back there for ya. Otherwise I too recommend running an independent circuit from the battery.
By the way, If a benz has a second full size battery its used to separate the starting circuit from the rest of the car. Benz hasnt done this in a while, tho. The battery for the starter will be in the engine bay and the 'main' battery will be in the trunk. There is also a small battery used to power the EIS.
Anyways, Ill see what i can dig up for ya tomorrow. Id hate to see ya damage that rear SAM. Its big bucks, man.
By the way, If a benz has a second full size battery its used to separate the starting circuit from the rest of the car. Benz hasnt done this in a while, tho. The battery for the starter will be in the engine bay and the 'main' battery will be in the trunk. There is also a small battery used to power the EIS.
Anyways, Ill see what i can dig up for ya tomorrow. Id hate to see ya damage that rear SAM. Its big bucks, man.
