Questionhey brian i have a 2004 volvo xc90 and it has fiber optic cables along with a factory amp under the passenger seat. i would really like to install and aftermarket stereo and possible a subwoofer. any tips on how to go about this and what head unit i might need would be great.
AnswerHi Colin,
Sorry about the long delay in answering your question.
It won't be possible to keep the factory amplifier working with an after-market head unit, and there's no adapter harness made to directly connect your new deck to the vehicle's speaker system, so some custom wiring will be required to replace the factory radio.
Metra does make a mounting kit for the XC90; the part number is 99-9225. This kit is designed for any single-DIN head unit; in other words, it will work with any standard sized CD player with a 7" x 2" face. To wire it into the vehicle, though, it will be necessary to extend the speaker wires from the factory amplifier location up to the radio cavity.
Assuming you have the basic 8-speaker OEM package, then re-wiring the speakers won't be too difficult. This is because the factory amplifier is only a 4-channel design, so the wiring can be converted pretty easily to the new head unit's 4-channel speaker output.
One other potential problem: the factory AM/FM radio tuner is built into the amplifier under the passenger seat. That means there's no antenna connection in the radio cavity; you'll either need to install an antenna extension from the factory amp location to the new head unit, or you'll need to install an after-market antenna that mounts to the interior glass. Unfortunately, I don't have any information on the type of antenna connection that's available at the factory amp location, so I can't tell you which option would be easier for you.
Hope this helps!
Brian
