I bought an aftermarket subwoofer and amp to install in my 2004 V70R.
I found the correct leads for power, ground, and audio and got that working.
However, there is a purple wire that is supposed to supply 12V when the stereo is on to activate the amp. It does not seem to work. Does the dealer need to download a code to activate that wire?
I also was getting a lot of engine noise in the two rear speakers after I wired it up... not sure why.

Any help would be greatly appreciated!

Gary

 

you can use an ignition signal from the column if you want to turn on the amp. As for the rear speaker noise, it may be due to how you wired signal to the amp. if you got signal from those speakers and ran the RCA wire with the power and ground wire, that could create a noise. other wise make sure the ground for your amp is very good. also could cause noise. If you are unsure of if the ground is good move it to see if the noise changes