Hello,

I have an Fiat Grande Punto from 2007 and I have an issue regarding AC heating.

When the temperature is set on MAX on heating and AC is on , the AC is blowing cold air and not heat air.

The normal heat it's working when the engine is warm.

Can anyone tell me what can be the problem?

Hi

Either:

An airlock in the coolant pipes..
Check they get HOT

Or

A failure of a plastic component in the airbox... common issue..
If it was manually controlled you would know how stiff to turn it had become

A motor just pushes until it breaks

https://www.fiatforum.com/panda/463031-100hp-heater-playing-tricks-me-help.html