powering a clarion 6.5 monitor

Hello,

I bought a Clarion 6.5" headrest-type monitor from a police auction last year "as-is" $15, and now hooking up to my fuse box of my 2005 Mazda Tribute to make a back-up camera\video system.

The Clarion VMA6593 monitor schematic that I downloaded, and the sticker on the back say that this unit needs 12V or (9V-16V) according to the manual specs, and 800mA to power on. 

When I connected it to a 10A fuse in my fusebox with the ignition on, and grounded the ground to the car metal , the screen would get a little lighter\brighter, but not power on fully.  

What am I missing here?  Looks like no transformer came with original harness or is there a better place to power this monitor from in order to get 800mA? Page 10 here shows the basic layout:  http://www.clarion.com/us/en/MungoBlobs/519/928/VMA6593.pdf

Thanks so much in advance!

George