Shouldn't be any connection between radiator and internal blower. Blower is located above the passenger footwell - worth checking that there is power going to it - one connector with two fairly heavy duty wires going to it. Sometimes just unplugging and reconnecting can sort it.....

 

Two very common problems that can cause this.

Does the Fan work on full speed but not on other speeds ? If so it will be the Resistor pack, usually failure of the Thermal Fuse.

The Fan itself could be seized and just need some lubrication.

Of course it could be something to do with the Aircon system, I know nothing about that as I didn't have the luxury of Aircon in mine !

There are lots of Threads about this problem, a quick search will give you lots of info.