Recently purchased a 03 ML320 with 122k miles and here are the issues it has.

-Transmission cooling lines are leaking....Is it usually the entire lines that need to be replaced?

-Hub noise....Sounds like its coming from front left hub

- No sound coming from radio. The car had to be jumped and I entered the radio code and I get no sound from the radio. I checked the fuses by the passenger side and under the hood and nothing. I dont see any fuses near the amp underneath the seat and no fuse near the cd changer.

- When I press the CD button on the radio It says No cd player installed. Even though there is one and its plugged in.

Do you guys think its the amp or radio that went bad? How can I test further?

And lastly. Driver Side Low Beam light clicks on and off. How can I tell if its the ballast or the actual bulb that went bad?

Thanks

 

Ive seen cooler lines leak befor there is copper washers that seal a the tranny an the upper trans line to the radiator is sealed with a copper washer... the lower line to the radiator is a standard non banjo bolt fitting... these lines usually leak at the couplers in the center (were the rubber hose is coupled into a metal line) if the leak is there u will need to whole line cause the coupler cannot be repaired...if u order from mb it comes w/ Both lines...

Could very well be a front wheel bearing would need to hear the noise myself

The audio system works with D2b optical wires... these wires tranfer signal to each audio component in the d2b ring..examp - headunit transfers signal via optical wire to cd changer,amplifier, somtimes teleaid then back to the headunit...if one of these items cant tranfer data to the next ...the result is no sound out of the speakers...my suggestion is to replace the cd changer that has the error..an i bet the volume will work..(thats the cd changer in the left rear of the vehicle)

The headlight flicker sounds like the headlamp control unit.. alot of them will get water intrusion an short out..but this only applies with xenon headlamps..let me know if there xenon

 

Well the sound doesn't even work for the radio either...You still think its the cd changer?

Yes I have xenon

 

you can try to pull the radio out, and unplug the fiber optic connection if it has one, and turn off the radio and then turn on the radio and look and see if the radio is giving off light from the fiber optic connection on the back, if im correct should flash a few times when you first turn on the radio.
you can also pull out the cd changer and unplug the fiber optic and turn the radio on and off and look at the fiber optic cable and see if you are getting light.

cd changers are a very common culprit with audio issues. you can unplug the fiber optic from the cd changer and get a loop out tool and eliminate the cd changer.
really hard to say, ive seen sound amps cause the same problems with the no sound.

 

I checked the fuse behind the radio and underhood. Both are good. I also unplugged the fiber optic cable behind the radio and turned the radio on...The red light blinks once for one second.

I replugged the fiber optic to the radio and unplugged the cable to the cd changer. It did the same. Blinked for a second.

I hear power going to the cd changer because it makes a power noise when i eject or insert the cd magazine.

I did the same to the amp and same result. Red light for one second.

Radio functionality seems to work, except for no sound and when i press cd it says No cd player installed.

The headlight issue has been resolved by replacing the bulb. The hub bearing noise was also resolved by replacing the front driver side bearing.

 

Ok i bought the Mercedes Benz Fiber Optic Bypass Coupler

I installed it on the cd changer first. I unplugged the telephone and when I turn the radio on i see one flashing red light.
Still No sound from Radio

I installed the coupler on the telephone. I unplugged the cd changer and when I turn the radio on I hear power going into the cd changer and i see one flashing red light.
Still No sound from Radio.

I installed the coupler on the amp. I unplugged the telephone and when I turn on the radio I see a red light behind the telephone unit and I also see a red light on the fiber optic cable blink once. When I unplug the cd changer I see a red light on the cd changer unit blink once and there is no red light on the fiber optic cable that connects to the cd changer.

Does this shed some light on whats wrong?

 

Its starting to sound like u need a amp ..I was leaning towards the CD changer but since u bypassed the d2b lines an still no sound I'm worried your amp is toast..you can't bypass this component with the tool because the d2b optic lines are what wakes it up to function. You half to have amp to have sound ...