Can anybody help with my 59 plate Focus heated windscreen problem.

I've looked at all the forums that I can find, yet none have described the issue I'm having.

When I press the heated windscreen button (whilst the engine is running), the light comes on as though it is working, yet the windscreen doesn't clear.

Just bought this car and it also has electric mirrors that don't work.

Hoping that these things aren't related or that I've just bought an electrical nightmare.

Any suggestions would be appreciated. 

I assume there is no warranty on the car ?

Fuses ?    is the first port of call ,for all of them.

Rear windscreen  make sure the connections  are on  on the glass part itself , look to see if you can spot any breaks in the  heating elements on the actual windscreen 

you'll need to get to the wiring connectors on the mirrors to see if they are actually connected   see you tube  on how to do this   

The other thing is that the electrical connection to the heated windscreen is very delicate and can be broken by the windscreen wiper motor arm rubbing against it under the scuttle panel - plenty of threads discussing this problem on this forum if you do a search.

have you checked it does have a heated windscreen and it has not been replaced with a cheaper screen without the heating elements in it. (the fine zig zag wires in the glass running from top to bottom all over the screen.)   I do recall someone a while back having this problem and finding it had a replacement non-heated screen fitted