[t_wirth]

I have a 2005 300c. I just installed a new cd player and now trying to add a subwoofer in the trunk. All the wires are hooked up correctly. The ground from the amp is connected to the same ground as the battery. It seemed to work fine when I first installed it but quickly turned out making engine noise or collecting noise from something else. My remote wires and rca plugs are ran from the back to front on the right side of the vehicle. The positive wire from my amp is connected directly to the battery which is a maintenance free battery located in the trunk. Any ideas what the noise could be coming from? or any ideas for improvement of my installation? Thank you!

 

[PGT]

you've got a ground loop. any other 12v accessories installed? Does your CD player have a chassis ground and an electrical ground?

you also need to make sure that the power wire to the battery comes nowhere near your signal cable (which it sounds like you did). What kind of RCA cable did you use? a quality shielded one?

 

[t_wirth]

the cd player has an electrical ground

 

[t_wirth]

hey thanks, all i had to do was adjust my RCA cables away from the amp power wire.

 

[Cool_V_300C]

For anyone else that sees this. If you follow the battery cable from the battery toward the front, You'll notice how it is routed. On the right side between the back seat and wheel well is likely the place where you are most susceptible to getting noise if you run your cables down the right side of the car. Basically there is a 2 gauge cable running from alt to the battery on that side.

One thing I did was take a right turn in front of the back seat before going into the trunk.
This avoided the "hot zone". My signal cables are routed through the center of the back seat.

As far as cables, you should try to get unshielded twisted pair. In some cases the shield may actually make your problem worse by actually acting like an antenna.