OEM amp bypass for 2000 ML55
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From: So Cal
07 GL450, 91 NSX, 12 Prius
OEM amp bypass for 2000 ML55
My audio just stopped working. My head unit worked correctly so I figure it must be the OEM amp. There was no fuse to the amp so I guess it blew. Since my headunit is aftermarket. (Avic-D3) I can wire the speaker straight to the Headunit. I bypassed the OEM amp, after about 1 hr of research on WIS and 1.5 hr of line testing and reconnection.
This is for 2000 ML55 with 4 speaker and Under driver seat subwoofer.
MB WIS - Sound Amplifier
I pull the OEM amp out and the part # is 163 820 18 89
It is located behind the dash. Go under and remove the under dash panel. Move the sound dampening material to access the amp. 1 10mm bolt mounts the amp to the firewall.
There is 2 harness to the amp.
Harness with 15 wires.
Signal from Head unit. (thinner gauge wires) (Bank B)
b8 Red & b10 gray = Right rear signal
b5 Blue & b12 green = Left Front signal
b6 Orange & b9 White = Right Front signal
b7 Pink & b11 Orange = Left Rear signal
To Speaker. (These are slightly thicker gauge wires) (Bank A)
a8 Orange & a7 White = Rear Front speaker
a12 Blue & a11 Green = Left Front speaker
a9 Red & a10 Gray = Right Rear speaker
harness with 8 wires
Pink & Orange wire = Left Rear speaker
If you map it out basically you match the color on the 15 wire harness. You will get one Orange wire left over that is not group together with the signal and speaker wires.
You have to match Pink & Orange with the 15 wire harness to the Pink and Orange on the 8 wire harness for the Left rear speaker. I found it odd they didn't put it to the same harness.
You will lose the under seat subwoofer.
This is for 2000 ML55 with 4 speaker and Under driver seat subwoofer.
MB WIS - Sound Amplifier
I pull the OEM amp out and the part # is 163 820 18 89
It is located behind the dash. Go under and remove the under dash panel. Move the sound dampening material to access the amp. 1 10mm bolt mounts the amp to the firewall.
There is 2 harness to the amp.
Harness with 15 wires.
Signal from Head unit. (thinner gauge wires) (Bank B)
b8 Red & b10 gray = Right rear signal
b5 Blue & b12 green = Left Front signal
b6 Orange & b9 White = Right Front signal
b7 Pink & b11 Orange = Left Rear signal
To Speaker. (These are slightly thicker gauge wires) (Bank A)
a8 Orange & a7 White = Rear Front speaker
a12 Blue & a11 Green = Left Front speaker
a9 Red & a10 Gray = Right Rear speaker
harness with 8 wires
Pink & Orange wire = Left Rear speaker
If you map it out basically you match the color on the 15 wire harness. You will get one Orange wire left over that is not group together with the signal and speaker wires.
You have to match Pink & Orange with the 15 wire harness to the Pink and Orange on the 8 wire harness for the Left rear speaker. I found it odd they didn't put it to the same harness.
You will lose the under seat subwoofer.
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Joined: Nov 2010
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ml 500
What is a good way to access the amp? Can't get on my back in the car as the driver seat in in the way
i am not able to remove the speakers connector to Amp when I have to run my hands through the front. I removed the bolt holding the AMP but it did not make it move much.
i am not able to remove the speakers connector to Amp when I have to run my hands through the front. I removed the bolt holding the AMP but it did not make it move much.
Last edited by voidy; Feb 22, 2011 at 02:45 PM. Reason: spell
Junior Member
Joined: Jun 2010
Posts: 20
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2000 ml5.5 amg
If you got the bolt out wiggle the amp around and it will come out. Note: 3 speaker connections are in one plug and 1 in the other. Hint: if you install an aftermarket radio, pick up power in the fuse panel on the right hand side kick panel. The 12 volt sources in the radio area drop to 8.6 volts when you put the truck in gear. (haven't got the foggest why)
My daughter claims the $120 Sony has better sound than the original.
My daughter claims the $120 Sony has better sound than the original.
Last edited by user973783; Feb 22, 2011 at 12:38 PM.
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Posts: 28
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ml 500
I have the lower instrument panel out ..but there is still plastic cover at hte bottom above the foot and gas pedel which I am planning to remove.
Will it wiggle down and fall to the brake and gas pedel area?
so all the speaker wires are not in this connector..can you post a pic?
http://t3.gstatic.com/images?q=tbn:A...LMBdf-Khkh&t=1
Will it wiggle down and fall to the brake and gas pedel area?
so all the speaker wires are not in this connector..can you post a pic?
http://t3.gstatic.com/images?q=tbn:A...LMBdf-Khkh&t=1
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Junior Member
Joined: Nov 2010
Posts: 28
Likes: 1
ml 500
in the first post
"It is located behind the dash. Go under and remove the under dash panel. Move the sound dampening material to access the amp. 1 10mm bolt mounts the amp to the firewall. "
"Go under", does that mean go under the car from outside? Because getting into the area in the gas/brake pedal is tough.
Much appreciated
Also found this in my search: Will this help?
http://www.justcarkits.co.uk/acatalog/info_479.html
"It is located behind the dash. Go under and remove the under dash panel. Move the sound dampening material to access the amp. 1 10mm bolt mounts the amp to the firewall. "
"Go under", does that mean go under the car from outside? Because getting into the area in the gas/brake pedal is tough.
Much appreciated
Also found this in my search: Will this help?
http://www.justcarkits.co.uk/acatalog/info_479.html
Last edited by voidy; Feb 22, 2011 at 02:43 PM.
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Joined: Jun 2010
Posts: 20
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2000 ml5.5 amg
No it's against the firewall under the insulation. To the left and above the brake pedal.
I'm 6' and weigh 240. Didn't have a problem.
As far as I know there is no plug kits available for the pre 2001 MLs. You will have to hard wire. (not a big deal)
I also had to modify a dash kit as there is nothing available for a 2000. Came out real good though.
I'm 6' and weigh 240. Didn't have a problem.
As far as I know there is no plug kits available for the pre 2001 MLs. You will have to hard wire. (not a big deal)
I also had to modify a dash kit as there is nothing available for a 2000. Came out real good though.
Junior Member
Joined: Nov 2010
Posts: 28
Likes: 1
ml 500
sorry for being a PITA, but I am just 130 lbs and 5.7 so should be easy for me.. so did you lay on your back near the foot pedel to work on it?
Update: Thanks for your help, got it out, but I have the fiber optic cable and the pin connector ..there was no other harness (since the first post did not have any pic i am not sure)
I am going ot be wiring it as below..
Update: Thanks for your help, got it out, but I have the fiber optic cable and the pin connector ..there was no other harness (since the first post did not have any pic i am not sure)
I am going ot be wiring it as below..
Last edited by voidy; Feb 22, 2011 at 07:10 PM.
Junior Member
Joined: Nov 2010
Posts: 28
Likes: 1
ml 500
Junior Member
Joined: Nov 2010
Posts: 28
Likes: 1
ml 500
when I say under the dashboard it means it is inside the dashboard and under the upper panel..sorry if I was not being clear. I could shove my hand through the glove compartment area and reach out over there .. so was thinking it would be a good spot..
Velcro/gorilla glue?
The only obstruction with it inside the dash would be leather trim and 1-4 mm plastic.
Velcro/gorilla glue?
The only obstruction with it inside the dash would be leather trim and 1-4 mm plastic.
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Joined: Nov 2010
Posts: 28
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ml 500
Ok ..here are some after pics ..
I am having one problem while driving ..the display will shout off intermittently
I am not sure but i think the problem I am seeing is becoz, I connected the VSS (Vehicle speed sensor) to the brake signal of the KingCObra HU. So when ever the vehicle is moving it probably generates a signal ..which translates to a brake (that sounds dumb) and it is shutting the display .. I will have to remove the unit to disconnect ..oh darn..
THe cobra HU has Brake and Back sensor wires I connected the "Back" to "Reverse" of the benz signal. I think that is good
I am having one problem while driving ..the display will shout off intermittently
I am not sure but i think the problem I am seeing is becoz, I connected the VSS (Vehicle speed sensor) to the brake signal of the KingCObra HU. So when ever the vehicle is moving it probably generates a signal ..which translates to a brake (that sounds dumb) and it is shutting the display .. I will have to remove the unit to disconnect ..oh darn..
THe cobra HU has Brake and Back sensor wires I connected the "Back" to "Reverse" of the benz signal. I think that is good
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2000 ml5.5 amg
Make sure that you are getting 12 volts when your in gear.
On the 2000 I got 12 volts but it dropped down to 8.6 when I put it in gear. I had to pick up 12 volts from another source that was solid.
On the 2000 I got 12 volts but it dropped down to 8.6 when I put it in gear. I had to pick up 12 volts from another source that was solid.
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Joined: Nov 2010
Posts: 28
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ml 500
Sure emough, the problem was connecting the Brake wire of HU to VSS sensor. I diconnected and now the display stays on.
Also when they were connected I was unable operate the HU when the vehicle is moving.. only after i can to a complete stop ..the unit would allow me to operate any controls..
The funny thing that would happen is I would try to take the vol up when driving and nothing would change as the vehicle is moving ..but as i stop at the light, the volume would switch to MAX at the stop. Very embrassing
Also when they were connected I was unable operate the HU when the vehicle is moving.. only after i can to a complete stop ..the unit would allow me to operate any controls..
The funny thing that would happen is I would try to take the vol up when driving and nothing would change as the vehicle is moving ..but as i stop at the light, the volume would switch to MAX at the stop. Very embrassing
