Suburban DVD/Gps TV Trouble

[chev3]

Hi all!
I am having trouble with my Suburban dvd/gps system. I can't seem to get the TV to work while driving. Anyone else have this problem?

Here is my system:
http://www.autocardvdgps.com/avalan...oe-suburban-avalanche-impala-monte-carlo.html

Thank you in advance!