Car Stereos: Aftermarket stereo will not stay on., 2004 ford freestar, vehicle speed sensor

Question
I installed an aftermarket stereo/dvd unit in my 2004 ford Freestar. The unit has power when the vehicle is running or turned on. As soon as I start driving, the unit appears to go off, the display and sound turn off, but the unit has power (power button is lit). As soon as I bring the vehicle to a standstill the sound and display comes back on and the radio or DVD function starts working. Any idea what could be causing this?

Answer
Hi Scott,

It sounds like you got a wire crossed somewhere.  My guess would be there's a vehicle speed sensor in the harness for factory dvd/nav units, and it's wired somewhere it shouldn't be.  Give your wiring a good recheck - I bet you'll find your answers there.

Justin