Hello!
I'm attempting an install in Father in law's 97 Avalon.
All the diagrams I've found indicate 2 connecters, and a blue / YELLOW +12v wire.
This car has a single connecter (single DIN AM/FM cassette, with a cubby below) and no Blue / YELLOW to be found, so the archives are of little help.
It's a Canadian car, although I don't think that makes any difference, as it was manufactured in Kentucky, along with all the other Avalons.
Help would sure be appreciated, as it's all apart in the driveway...:errr:
Thanks!!
Mike.
The plot thickens!
I put the factory radio back in, and.... No power. It says "anti theft" on the cassette door, so I go to the owners manual... Apparently, a code needs to be set for that function, don't think it ever was, but either way I get no display on the radio prompting me to enter a code when I press the buttons indicated to enter a code.. Fuse is OK, and the lighter (same circuit) works.
The music from "The Twilight Zone" plays in my head.
If you can't find the code in any of the cars paperwork, call your local Toyota dealership, transfer to Parts (it may be Service), and ask them for the code! You'll probably want the stereo in hand so they can get the #s off of it.
Oh, yeah... What you should try is to match up the wires you DO have and go from there.
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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Are you using a wiring harness? If the factory radio has a single connector then you need the amp integration harness for your vehicle, Metra 70-8113 I think. 2 connectors and you would use the 70-1761. Also you should consider picking up a cheapo dmm to test the fuses. In my short time installing I came across at least 3 fuses that "looked" good but didnt register continuity on the dmm
Dang.
Since it's not an XLS like my wife's, and only 4 speakers I didn't think about an amp. Might explain why I couldn't pull more than part of a volt from any of the wires in the harness. 
Anyone able to offer any clues or a link to a page that'll have info about this amp? I'd rather bypass it and run with the head unit power at this point, ASSuming I don't have to dissemble the whole car to find it.. Hopefully there's the 12v, switched 12v, and speaker conections there that I need.
Hopefully the speaker are 4 ohm, if not, I really have my work cut out for me.
I don't have a diagram for 1997 but I'm pretty sure 1998 is the same
1998 Toyota Avalon radio diagram