Originally Posted by brads9191
I'm really not sure how an interface helps though. I just remembered, when I plugged the stock unit back in, it came on and worked perfectly fine without the 10 pin connected being plugged in. So why wouldn't the aftermarket unit work without it?
Hmm, that is odd, the switched power is supposed to come from one of the pins of the 10 pin, I am not sure how the factory unit turns on without that 10 pin being connected.
Does the stock unit actually work without the 10 pin, or does it just illuminate the display?
I am looking over the info from that PDF I linked you to, and I see there is one wire of the 24 pin connector mentioned that is not used for the aftermarket radio, the Orange wire, I wonder if that provides turn on power for the stock unit, if it does I cannot see why there would be another one as a part of the 10 pin.
If you have a multimeter you could set it to 12v, and ground the ground lead, then look for any red, orange, or yellow wires coming from the 10 pin connector, turn the car to ACC, or ON, then test the wires till you find the one that have 12v, once you find it try turning the key to off, then opening the doors, when you find the one with 12v that cuts off when you do this, then that is the wire you want to use for you aftermarket stereo'* switched power wire.
Once you find it I am not sure of a great way to tap into it, they make t-taps that you can use to keep from needing to cut the wire, but I am not a fan of the t-taps.
I'd just use the ATC type tap that Justin linked you to, and run a wire from the switched power at the fuse box.