Now you have to get to the factory amp, which is behind the glove box.
Start by removing the right kick panel. It has a plastic bolt, then you just pull it off.
Your next step will be to remove the L shaped trim panel, with also has a cover attached to it, behind it. This cover came off easily as I removed the L shaped trim panel. The L shaped trim panel has three bolts. Two are easy to see. The third you have to open the glove box and remove a cover to see:
http://drri.home.comcast.net/avalon/..._trim_bolt.jpg
After you removed the bolts, you will pull off the L shaped trim piece. I had to play with opening and closing the glove box door while getting it off. This next pic will help so you know where the tabs are that holds it in.
http://drri.home.comcast.net/avalon/...trim_clips.jpg
The glove box door comes off easily with three bolts.
Four screws hold the actual glove box, and there are connectors that have to be removed, including one that I think runs to the air bag (oh year, before you batter is disconnected). You will have to work a little to get the glove box proper out.
When you finally get it all removed, this is what you will see:
http://drri.home.comcast.net/avalon/amp.jpg
That is your factory amp on the right, with two connectors in it. It is attached with two bolts on the rear side of it.
Here is a closer look at the plugs:
http://drri.home.comcast.net/avalon/amp_plugs.jpg
What I did to work with these was to cut back the insulation about an inch. It’s tight, but there was enough room to reach through the glove box, strip wires, and attach new wires. If you do not have a wire stripper already, buy the smallest one you can. Mine is quite large and was cumbersome to work with.
You will basically end up running 10 wires from here to new head unit (8 speaker wires, constant power, and accessory power).
You can consider the blue (white in some Avalons) one the output—out to the speakers, and the green (grey in some Avalons) the input-inputs from the head unit. From the input one you will only draw your Accessory Power. Not sure why, but Crutchfield recommended drawing power from the one I am designating output.
Here is the wiring schema for each plug courtesy of Crutchfield:
White or blue plug at amplifier (output)
FUNCTION / WIRE COLOR
Right Front SPKR + / LIGHT GREEN – this and the next 3 go to new HU
Left Front SPKR + / PINK
Right Rear SPKR + / RED
Left Rear SPKR + / BLACK
Woofer + (7th SPKR) / GREEN/BLACK – missing on mine
Constant 12 Volt Input / WHITE/BLUE – where I drew power
Right Front SPKR - / BLUE – this and next 3 go to new HU
Left Front SPKR - / VIOLET
Right Rear SPKR - / WHITE/BLUE
Left Rear SPKR - / YELLOW
Chassis Ground / BROWN – the ground I used
Chassis Ground / BROWN
Woofer - (7th SPKR) / GREEN/RED – missing on mine
Constant 12 Volt Input / WHITE/BLUE
Gray or light green plug at amplifier (input)
FUNCTION / WIRE COLOR
Remote Turn On / RED – you could do your antenna power here, or where I mentioned earlier
Accessory 12 Volt Input / GRAY – where you get your accessory power
Constant 12 Volt to Radio / WHITE
Beep Input from Radio / BLACK
Left Front SPKR + Input / GREEN
Right Front + Input / RED
Illumination Input / GREEN
Illumination Output to Radio / GREEN
Accessory 12 Volt to Radio / BLACK
Chassis Ground to Radio / BLACK
Signal Ground Input from Radio / BROWN
Mute Input from Radio / BLUE
Left Rear SPKR + Input / WHITE
Right Rear SPKR + Input / YELLOW
