[Scotturch]

Got jump started by rac and ever since my radio and sat nav screen ent working ford focus 2012

[Beelzebub]

OP, when the car was sold originally the buyer would have been given a code to reset the radio, probably among the paperwork (handbook, service record, etc.). If you can find that, then the handbook will tell you what to do.

Otherwise, speak to a Ford dealer.

[NMNeil]

First thing to check would be fuse 67, which controls both.

[Scotturch]

I have buddy took that fuse out and changed it still no luck

[Scotturch]

@Beelzebub u carnt get the code buddy the screen blank

[NMNeil]

Then some expensive module probably got fried.
I design and build simple electronic projects and I always put a reverse voltage safety circuit in place, either a diode and fuse or a P-channel mosfet.
Manufacturers don't because the extra components increase cost and if someone puts jumper cables on the wrong way round it benefits the manufacturer to have the module fry, so you have to buy a new one.