Hello,

I'm installing a sub/amp in the trunk of my 2006 MCS this weekend. I have an idea but need some advice.

The amp requires 4 lines/cables

1. Red 12V constant power
2. Black Ground
3. RCA's
4. Yellow 12V power-on wire

#1 and #2 are easily accessible from under the matting of the trunk (since the battery is located there).

The RCA lines will be run to a converter. I'll splice the input leads of the converter into the rear speakers.

The problem is with the 12V power-on line. I know there is one behind the stereo console but the thought of pulling seats and floorboards is anything but appealing to me.

My question is this:

Does there exist a 12V power-on line next to the battery or in the rear tailight compartments and if so, WHAT COLOR IS IT? If not, is there another line that can act as a 12V power-on line that I could use? Finally, if neither of these solutions exist, then what color is the power-on line coming from the back of the stereo/receiver?

Thanks in advance,

Placebo

 

There is a wire useful for this near the back, on the right side. Inside the rear seat trim panel under the window is a 'diversity amplifier' that takes the FM signals from the roof antenna and the rear defroster grid (which is also used as an antenna), routing the strongest signal from either of these to the radio. There are three coax cables leading to this device, and a white wire. This white wire has 12 volts on it when the radio is on. This wire, however, cannot supply very much current, which is usually not a problem if used as a trigger wire for an amplifier. Just dont try to run anything that draws more than a few milliamps, it can cause damage or malunctioning of the headunit.

Only problem about using this wire at the diversity amplifier is the need to remove the entire rear interior piece to get to it.

You can also find this wire at the headunit cluster connector. It's again the solid white wire.

 

Most people use the 12 source that is located in the boot which powers the 12v accessory plug (driver's side power outlet). Just tap into the +12v side of this line and you'll be fine......
One piece of advice is TRY NOT TO PUT THE AMP ON TOP OF THE BATTERY. I did that when I first did my install. THe result was lots of high pitch engine whine coming through my speakers. I tried many many different things to fix this problem with very little success.
THe concensus on the problem is that there is a RF field being put out by the alternator current coming into the battery which is picked up by the power/rca lines coming into the amp. Even the most expensive shielded rca lines didn't fix my problems.

Good luck and have fun with your project!
Donald

 

Thanks guys...

Soilsample, you wouldn't happen to know the color of that 12V line would ya? Also, I plan on putting the speakerbox in the boot and then mounting the amp on top of the box. The amp will be 13-15 inches away from the battery.

Is this still too close?

-Placebo

 

If you take a look in the boot..... open the little compartment on the driver's side. You can see a grounding block fastened to the chassis......
I believe that the solid brown is ground.

I'm not sure about the distance from battery to amp. You'll probably be Ok, my amp was directly on top of the battery. Other suggestion would be to use a good solid ground point for your amp. Some people say don't ground directly to the battery.

Good luck
Donald

 

Soilsample,

I see that all the brown wires are the grounds, but what color is the 12V power-on line which you speak of?

GreatBear,

How few is a FEW milliamps. I think my Rockford Fosgate P3002 will draw around 50 milliamps (not sure, still trying to find exact specs on this.) Is this too much for the 'diversity amplifier'?

Thanks,

Placebo

 

50mA should not be a problem. I was doing some experimenting and found that a draw of about 300mA was the limit before the supplied voltage began to drop.

The advantage of using this as a turn-on wire is if you are using a stock HU, you retain the ability of turning on the radio with the key off and still have your amp, etc, power on and off with it. I used the line to trigger a small relay which powers on my Sirius receiver. Also, since I have an '03, my stock boot power outlet was lost in the Bermuda Triangle along with every other MINI shipped that year. I added my own continuously-powered outlet, so I have no accessory-switched source back there.