Here are the parts I used:
DB9-RJ11
12VDC/1A SPDT Micro Relay
I wrote my own interlock app but I had recently switched to Frodo and it's working perfectly. Vis, Video, and DVD are locked out. Video and DVD still plays and has audio. Only the picture is disabled.
This is a real easy and cheap mod and gives you failsafe defense when you get pulled over so I'm wondering why people are kinda indifferent about it

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