Maxweisen

Hello,

Another Bose audio issue? Yes!

Vehicle: 2003, Mercedes ML500 (With Bose Fiber Optic Audio)

Problem : I have no sound coming from my speakers

Things I have done:

1. Original headunit did not have 4 red flashes from the fiber optic port. I replaced the headunit with another identical model. Fiber optic port blinks red 4 times at startup

2. I replace the original Bose amp with another identical Bose amp. (no change)

3. I tested port 26 of the wiring hardness going to the Bose amp. I get 12v when car is ON.

4. I used 2 fiber optic dummy plug to close the fiber optic loop off from the CD CHANGER and the TELEPHONE UNDER PASSENGER SEAT
*Now that the TELEPHONE and CD CHANGER are OUT OF THE FIBER OPTIC LOOP. That leaves the BOSE AMP and FACTORY HEADUNIT as the only items active in the loop.

5. I have checked every fuse, in the engine compartment and in the passenger foot well for continuity, and they all pass.

6. I checked the fuse on the factory headunit and Bose amp for continuity, they both passed.

7. When I used a fiber optic dummy plug on the Bose amp's fiber optic line, I could see the red flash on both the telephone fiber optic and the CD changer fiber optic.
There was no red flash on those lines with the Bose amp connected.

I am not sure where to go from here as I have replaced both the amp and the headunit.

Does anyone else have an idea of where to go next on my troubleshooting adventure?

Thank you to everyone taking a minute to read my situation.

- Max

Maxweisen

UPDATE

I just met with the original owner of the ML500. He gave me ANOTHER headunit and Bose amp.

So I swapped them out again and we still do not have sound. So I think it is safe to assume that I don't have 3 bad amps and head units.

I am seriously stumped here.

- Max

Maj. Dundee

Have you seen this repair?

Maxweisen

Thanks for sending. First time I have seen that and I did not know splicing fiber optic was possible.

Maj. Dundee

Let us know what happened.

Maxweisen

Nothing has changed. I do not believe that the cable is damaged as I have been able to get a red light from each component in the Fiber Optic ring.
Unless I find a section of cable that's damaged, I do not see any spot that requires splicing.

Maj. Dundee

Sorry to hear, but I have nothing further.

ChrisVannoy

keep us posted

Maxweisen

Hey everyone. I took the ML to a friend who works with car audio and his recommendation is to scrap the system and go aftermarket.

I had a feeling that was going to be the consensus.

Thanks to all that responded.