Hi everyone, Im a newbie so dont know much about forums but needed help with my carputer setup.

i have these:
Carnetix p2140
Extron 109xi scan converter
OEM acura tl navi w/touchscreen
USB touchscreen board from Tvielectronics
Relay- all five items from DigiKey
Mac Mini (new Model)
MacPak power cable for Carnetix
PC cercuit board from RadioShack

what i want to know is do i need a switch and relay?
do i need a ac/dc inverter for the scan converter to have power?
how do i EXACTLY connect the relay with the 4pin on the acura navi?
is there any videos or pics on how to do the relay and switch? i found some but they are the final outcome which doesnt help much

THANKS MUCH FOR ALL THE HELP I GET