l have a fiat punto mk2 (2003) and the heater does not work we have replaced the heater switch replaced the heater element we know the blower works as we have tested it , when you turn the heater swicth on the side lights come on but no heater has anyone got any ideas please

Sounds like it is wired up incorrectly, go see a proper mechanic and explain exactly what the problem is, the light should not come on when the heater is switched on!

Double check the wiring/fuses again - do the side lights come on when you switch the lights on ? Does the car run smoothly, or does the engine run roughly, misfire,overheat ? Possibly worth getting the head gasket checked, as no heater could be a sympton of that, particularly if you have previously replaced the heater components. Best of luck.