Rear turn signals & Audio not working
Thread Starter
Newbie
Joined: Jun 2019
Posts: 14
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From: Las Vegas, NV
2008 CLK550
Rear turn signals & Audio not working
Hi, I just acquired a 2008 CLK550 and have been using this forum to trouble shoot several issues for about a week now and have learned a lot. However, I still have two major problems I need help with. Forgive me if my terminology is not spot on, but I'm a recently single female, trying to fix my car on my own and this whole car repair thing is new to me.
Problem #1 - Rear turn signals not working. I have checked and/or replaced all of the fuses in the car. I replaced the bulbs. The brake, back-up and reverse lights work fine. The left turn dashboard indicator flashes and clicks rapidly and the right one blinks at a normal rate but neither light works. I have checked for any disconnected or loose wires in the immediate area of the light assembly and found nothing.
Problem #2 - No sound from the audio system. Everything appears to be working per the display, Navigation and CD's can be loaded and ejected, can operate scan and seek for radio, but no sound. There is a CD changer in the glove box that doesn't seem to work. Nothing happens when you press to eject magazine and it isn't recognized in the display window (unless it's noted as Aux in the upper right corner of the display) Again, I have checked and/or replaced all fuses but that's as far as I got. I read here that all components are on a continuous loop and if one of them is not working/connected it affects the others. Should I start further trouble shooting by pulling and checking the CD Changer? I am so fed up and frustrated at this point, UGH, but taking to a dealer isn't really an option right now. Any help or suggestions would be appreciated.
Problem #1 - Rear turn signals not working. I have checked and/or replaced all of the fuses in the car. I replaced the bulbs. The brake, back-up and reverse lights work fine. The left turn dashboard indicator flashes and clicks rapidly and the right one blinks at a normal rate but neither light works. I have checked for any disconnected or loose wires in the immediate area of the light assembly and found nothing.
Problem #2 - No sound from the audio system. Everything appears to be working per the display, Navigation and CD's can be loaded and ejected, can operate scan and seek for radio, but no sound. There is a CD changer in the glove box that doesn't seem to work. Nothing happens when you press to eject magazine and it isn't recognized in the display window (unless it's noted as Aux in the upper right corner of the display) Again, I have checked and/or replaced all fuses but that's as far as I got. I read here that all components are on a continuous loop and if one of them is not working/connected it affects the others. Should I start further trouble shooting by pulling and checking the CD Changer? I am so fed up and frustrated at this point, UGH, but taking to a dealer isn't really an option right now. Any help or suggestions would be appreciated.
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Joined: Dec 2009
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Welcome tot he forum!
The turn signals are not powered through a fuse. They are controlled and electronically fused by he rear SAM (Signal Acquisition Module, a small computer in the trunk which is part of the fuse panel there). Since you have replaced the bulbs, my guess is that it's a wiring problem. Check the bulb sockets for corrosion. Check the wiring harness on the tail light assembly for any obvious issues. Try swapping bulbs from side to side.
The radio problems sounds like the MOST fiber optic loop is "broken". The CDC could be the culprit. You said you replaced the fuses, but check #20 (in the trunk) to make sure it's good - it controls the CDC. If you suspect the CDC is bad, you can remove it and bypass the it on the fiber loop. Removal is easy - there is a single screw in the "roof" of the glove compartment housing holding its front right corner in place. Remove that and you can pivot out the whole CDC. You can by a MOST fiber coupler/bypass adapter to complete the fiber loop once it's removed.
The turn signals are not powered through a fuse. They are controlled and electronically fused by he rear SAM (Signal Acquisition Module, a small computer in the trunk which is part of the fuse panel there). Since you have replaced the bulbs, my guess is that it's a wiring problem. Check the bulb sockets for corrosion. Check the wiring harness on the tail light assembly for any obvious issues. Try swapping bulbs from side to side.
The radio problems sounds like the MOST fiber optic loop is "broken". The CDC could be the culprit. You said you replaced the fuses, but check #20 (in the trunk) to make sure it's good - it controls the CDC. If you suspect the CDC is bad, you can remove it and bypass the it on the fiber loop. Removal is easy - there is a single screw in the "roof" of the glove compartment housing holding its front right corner in place. Remove that and you can pivot out the whole CDC. You can by a MOST fiber coupler/bypass adapter to complete the fiber loop once it's removed.
Thread Starter
Newbie
Joined: Jun 2019
Posts: 14
Likes: 1
From: Las Vegas, NV
2008 CLK550
When I replaced the #20 fuse for the CDC it sparked and stayed lit up, so I guess something made it blow, correct? I got another fuse which also sparked but its not the kind that lights up when blown. CDC still doesn't work. Why is it sparking and how do I determine if the second fuse is blown too? Dumb question, but does that mean there's an electrical short in the wiring?
MBworld Guru
Joined: Dec 2009
Posts: 10,782
Likes: 1,011
NO LONGER ACTIVE
Yes, there is a short in the wiring, or maybe a failure inside the CDC itself. I'd remove it and see if you can find any obvious issues with the electrical wiring plugged into the back of it.
MBworld Guru
Joined: Dec 2009
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2007 CLK350, 2014 B-Class
Thread Starter
Newbie
Joined: Jun 2019
Posts: 14
Likes: 1
From: Las Vegas, NV
2008 CLK550
I appreciate your apology. In that post, I was merely trying to convey my desperation by establishing the fact that I am attempting to tackle these repairs on my own and am completely void of any knowledge re: auto repairs. I hoped that any responses would, therefore, be relayed in basic easy to understand terms.
