Is there a second plug for the radio in the vehicle? On the back of both of my radios there are two female plugs-ins. The main radio plug (large) and a smaller one which I think is for an amp which I figured could have been ordered with the vehicle. That seems to match with what I saw available parts wise as there were two different factory face plates from Toyota. A thin opening with a storage compartment on top for the basic radio like I have or a wide opening and no storage compartment. The bigger opening got the better radio, disc or tape player. These were stacked on top of each other and took up the space where the storage compartment was with the basic radio. My LJ had both plugs but I only used the large plug. The vehicle was built with both plugs ready for whichever radio was specified I guess.
In addition the newer cars and radios, don't know how new, had additional wires to dim the lights through the rheostat on the light switch. My LJ does not have any dimmer at all. Only 12v in the plug to turn on the light on the radio.
On a few of the harnesses I found on line there was a wiring color code chart that was listed. That may help you decide what will work too.
