haloo!
I need help how connect my old tv ha s a atypical mini din 5 AV i need the schematic circuit 

on internet nobody is to know?
You could try using something like this Adapter Cable...
"Converts any S-Video port into RCA composite video port. 6" S-Video Mini4 Male to Composite Female Adapter. Item# CSV1RCA - Sale Price: $2.95" From...
http://www.sfcable.com/CSV1RCA.html?utm_medium=shoppingengine&utm_source=googlebase&cvsfa=3023&cvsfe=2&cvsfhu=43535631524341&gclid=CKLp26jkxLsCFcVQ7AoddhwABQ
You could use a standard Composite Cable to connect this from your Pi to your Car Video Monitor. This will be the reverse, of it's intended purpose. But, I think it would probably work. If you want to Convert the HDMI Video Output. There may be a Converter available. But, it may cost a bit more money. I didn't see one, in my initial searches. Here's more links to different types of Video Adapters and Converters...
Don