Ford Fusion does not start

Good, I have a Ford Fusion, and I had the starter engine that sometimes did not work, I changed it x another one that I got in 1 scroll that if I worked because I bought it. At trying to start the car does nothing and a lucecita of the panel in shape gives a key flashes, they have told me that it will be the key that has been decoded but I have caused with the other and nothing. Call one that encodes keys at home and could not tell me that it will be something else. I don't know what can be ... any suggestion? Thank you

Can it be the immobilisator or antirobo that is activated, turns on the rest of the lights or just that of the key?

The other lights do, the light that flashes is not a key. It is a car with a lock. If the choche is without contact, it flashes slowly but how much I give the contact flashes fast and the car does nothing. Thank you

mmmm short current does it have installed? The start is extended or not to reach the current?

Corta current does not carry, and the start does nothing does not reach current.