radio connector question

[irv6744]

i changed out the basic stock radio in my 2006 limited with the scion t1807, using castalucci's removal instructions and i am real pleased with the new radio.

there is one unused connector on the back of the radio and i was wondering what that is for.

thanks

 

[qballjr13]

I personally dont have that HU but I would bet that it is probably for a CD changer. I am sure others will confirm.