'99 XLT... 2 plugs only used one...

[SplashMan]

I finally installed a aftmarket HU into my '99. It works great, no problems at all, but there where two plugs in the stock radio, but I only needed to use one to make my new HU work... what is the other plug for? I was thinking maybe the rear radio controls?

 

[mab668]

on my 2000 xls the second plug had one wire going to it I bought the car with the basic sound system because I knew I would rip it out but any way that kept the power on for like 20 min after you turned the key off or in till you opened the door but I would imagine that plug would also be for any options you have as well steering wheel control rear controls things of that nature

 

[mrpeaches]

mine had that too, i think it was for the door thing, cause it doesnt work anymore.

 

[SplashMan]

I don't know what level my radio is, it has a CD player, but that is it. The only things that don't work after the HU install are the rear controls.
I guess it isn't a big deal, I was just wondering.