Ford Repair: radio does not work, factory radio, battery terminals

Question
My battery died, and I used cables to start it.  Unfortunately, I crossed the wires.  Right after I did that the radio did work.  What happened?

Answer
Angelo,

Unfortunately this may be the start of many problems to come. When you reverse the battery terminals it causes a direct short in the entire electrical system. First check all your fuses with a test light. Both under the hood and under the dash. You should have power on both sides of the fuse if it is good. Next, get your alternator tested by a shop. The diodes are subject to damage when your cross them like that.  If everything else is ok then you will need a new radio.  If it is not a factory radio, be sure to check behind it for fuses also.