Hello, I bought a 160W factory amplifier and was going to install today, but it doesn't seem to fit behind the head unit as all the research I completed suggests. Does anyone have any installation instruction and diagrams to show where it goes? Also, when I plugged it all into the back of the head unit while I had everything apart, I could not hear any difference in the sound whether it was plugged in or not??? And lastly, for some reason when I put my head unit back into the dash, I know have any issue when I turn on the heater blower fan, it cuts off the radio / cd player and everything is plugged into the back of the head unit correctly. Any suggestions? My next step is to either go to the dealer and see if they can install the amp and correct all the issues, or go to a stereo shop (which they will probably want to install all aftermarket items). I really like the factory units and when it works sounds great with all the infinity replacement speakers I installed and the 200W sub in the trunk that is wired to the back speakers - everything worked fine for the past 5 years that way.

 

Did it come with the bracket?

It is supposed to fit under the radio in front of the heater core.
This should help..
http://www.matthewsvolvosite.com/for...hp?f=1&t=30204

 

Yes, it came with the bracket and wiring harness, but there is one plug that does not have anything going into it. The smaller of the plugs on the back fo the head unit - I tried plugging that into the wiring harness of the amp, but then there is nothing to plug into the back of the head unit and sound only came out of the dash speaker when I did that, so I plugged the small one back into the head unit but then it does not go through the amp. Maybe I am missing a connection?

 

correct me if I'm wrong, but maybe it should go under the passenger seat? from what i have read some amps were installed there as well as behind the head unit

 

The one I purchased matches the photos of the amps that were installed behind the head unit.

 

The amps do mount right in front of the heater core. You should take the large plug out of the radio and plug it into the amp. Then the plug from the amp goes into the back of the radio. Also the small amp plug goes into the back of the radio. I think it turns the amp off and on.

As for the sound... There are a couple series of the radio. The SC-7xx series have low watts, they should bad under any pressure and the amp will make that system sound 50 times better. Then you have the SC-815+ series radios. They sound pretty good because they have 100 watts. When you install the amp on those you really don't hear a sound difference until you push it a little. Then you hear the deeper sound range and stronger bass response. But you really don't hear it under moderate levels.