ludwig14

Hello,

I'm new to this board and have a few questions about my 2004 CLK500. I had a local stereo shop install a system for me. Now I have a constant low level sound when the sterio is mute. I can hear it the loudest early in the morning.

They charged right around $350 to do the job...FYI They have tried about 10 times to figure out what the problem is. and they keep telling me that its the head unit. I can see why this would be a head unit issue, when all oter functions are intact

I have:
Pioneer F90bt
Eclipse 4 channel amp
Eclipse 2 channel amp
1 12' Image dynamics D2 I believe

PLEASE HELP!

dynomite05

Hello and welcome. There are a few audio heads on here that will probably be able to help, just give them some time.

bheng

is this when you are listening to the FM stereo, CD, or ipod...or all?

ludwig14

its at all times. only noticable at low volume or mute.

Kevwood

Sounds like ground loop noise to me. Check to make sure you have a good common ground (unibodies are known for occasional poor grounds) and that your RCA's are of good quality and not routed with the power wires.

ludwig14

I think you're right. My h/u has 3 rca out, so it has a small cable for each. Whats the best way to loop them? And whats the best ground to use?

Kevwood

You don't actualy loop them, it's just a term used for grounding issues. A good RCA cable is a must, I competed in IASCA sound quality so I always use a high end twisted pair with tinsel drain. As for the ground, I ran a 4ga ground line from the battery to the trunk and grounded it every 2ft. Not a hint of noise in my system and all the vehicles electronics benefit from a good solid ground.

ludwig14

Can you please send me instructions/how-to?

Kevwood

First and foremost check and make sure that the RCA's are routed together and away from the power line. And something to keep in mind, it could be the head unit (although unlikely), I had a bad one many moons ago that did the same.

Second, if the RCA's are isolated, ensure you have a solid ground in the trunk where the amps are grounded (ie, paint was removed and a good self tapping screw it tight. Also check the head unit ground. I never used the ground wire in the harness, I always ran an extra ground immediately to the chasis.

After the above is confirmed, if you still have noise run a new or spare RCA from the head unit to the amp 'free air', or in other words, just draped across the interior - this way you have a different cable and you'll be 100% sure that it's away from all electrical sources. See if you still get noise.

Pain in the a$$ isn't it? That's why I always did my installs as mentioned above, never any problems and never any time consuming trouble shooting.

Good luck.