Climate fans not working on levels 1-3, only work on level 4

[Lewis E]

When using my heating or AC when switching the levels of air, it only works on 4 not on any others, how would i fix this?

[AndyR]

Hi I had this problem with my Astra when I bought it. It turned out to be the Heater Blower Motor Resistor.

It was an awkward job to do, but once replaced, all controls were back working as they should. 

If you have a Haynes manual for your Corsa, it should show you where it is situated. On my Astra, it is at the bottom of the heater motor on the passenger side. It just plugs into the motor casing, and has electrical connection. 

Hope this helps. 

Andy.