Volkswagen Polo Horn Problems

With the heater turned to the cold position, periodically very hot air passes from the ventilators

The heater on my polo is only blowing hot air. Doesn't matter where you set the dial to, cold or hot, the temp of the air is the same? It has climatic with AC. Any ideas what the problem could be?

Electric windows and central locking not working, changed the fuse and still not working

When I connect my battery the starter motor engages even without key in ignition