when i use the key in the door the doors lock but as soon as i push the button on the key nothing works, i have changed the battery but still nothing.

The Car is a 2002 Fiesta Zetec-S

CheeRS Darren Lindsay

 

you might need tyhe key re-programming... some keys are coded to the car, so they dont unlock a similar car parked next to yours, and also to help stop some one with another fezza zetec s unlock your car with there key,
when you change the battery or even when the battery goes completely flat you have a certain limit of time to renew the battery beforen the codes are los in the key and it needs re-programming

 

the battery in the car has never went completely dead and i changed the battery in the key as soon as it stoped working so hasnt been more than 24hrs

 

I think there are instructions in the handbook about reprogramming the key. RTFM

Alternatively - a two second Google search brings up the answer:

FORD Fiesta 96> & Escort 98> (Radio 3 Button) - Key Remote Programming
1. Insert Key and turn to II, then Turn Key from II to I and back to II four times within 3 seconds
2. The PATS LED should light. Turn Key to Position 0.
3. Press the Unlock button and keep it pressed until the PATS LED flashes 4 times.
4. Add additional fobs the same way. Turn to II and back to 0 to end.

 

CheeRS mate worked a treat