Head unit replacement with tablet.
 

I have a 2003 RX-8 jap Import. the head unit was out dated no AUX or bluetooth, not to mention the radio only scans for jap channels. So instead of messing about doing little fix ups and patch jobs I thought to pull it all out and put in a nexus 7.
So i pulled it all out radio board and cd headunit. When i re connected the heating console at the bottom however i could get no response from it, yet the hazard lights connected through the console are working indicating power is still working through the console.
Any ideas what I've managed to screw up and how to fix them. looking to avoid getting ripped by a local mechanic or stealership

https://www.rx8club.com/series-i-interior-audio-electronics-24/