I have 7 inch display which I used in my car almost 10 years back I want to use it with my Rpi3b+. I tried changing various display modes in config.txt like sdtv mode =0 and other numbers. None of them are working. Sometimes screen blinks but it doesn't work. This display has two video inputs and works with 12v seperate power supply. I am using composite cable for connecting rpi to this display.
I tested with various tutorials like press shift key until green light stops blinking then press 1 2 3 4 which will redirect output to composite. It didn't work. I tried hdmi_ignore_hotplug=1
None of these are working. Can somebody guide me how to make it work. TFT LCD works perfectly with my analog camera.