1998 avalon stereo

You probably have a system with a seperate amplifier in which you will have to tag into wires at the amplifier or run separate wires to each speaker :( The amplifier is a square box sitting in around the radio area.

I have the same problem as well... By any chance, did you maybe know where is the amplifier box is? Do you mean the amplifier box could be under the dase ,or behind the stereo?

1998 toyota avalon xl is a unique oem radio. As you may know the audio wires goes to the amplifier, the amplifiers output connects to speakers. The wires from the radio however is only single wires (i.e for left speaker one wire goes) to the amplifier. The amplifier then convets to a two wire output to the speaker. Once you realized that, its simple, the aftermarket radio which has two wire output needs to be connected to the speakers directly. Which means find the amplifier, unplug the output connector, connect the output to the aftermarket radio. good luck