fkong777

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.

dj_lex

is there a way to keep the subwoofer? thanks

hcetzneb

Good diy work... on some of those amps there is a fuse on the amp(under the connection)
some times they will work again with a hard reset

user973783

I did the same thing. The amp is high up on the LEFT side of the firewall. I put in a SONY. Sounds good and it has USB port for my Ipod.

voidy

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.

user973783

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.

voidy

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

user973783

Yes

voidy

Sorry, I did not follow when you said 1 speaker wire is in the other connector..where is the other connector? Is it on the amp?

user973783

The amp has 2 connectors.

Read the first thread in this post.

voidy

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

user973783

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.

voidy

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..

user973783

What year truck do you have. Mine is a 2000 and I had harness plugs on the Bose Amp.

voidy

i have 2004 ml500

voidy

Gave it a test run with the connections and it sounds great ..

Few questions:

1. Would sticking the GPS ant below the dash board do?
2. Why is the subwoofer not connected? Is it becoz we are bypassing the AMP?

user973783

1. Not usually. does the GPS still work? I'm surprised.

2 You got it.

voidy

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.

user973783

try it

voidy

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

user973783

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.

voidy

Ok, will check if the shut off occurs when i put it in gear.

voidy

No just putting it in gear does not affect the display. only when driving.

voidy

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