I am looking for Chevrolet Spark 2010-2013 but I don't know what are the differences in UK between Plus, LS, LT and LTZ... can anyone help?

Why don't you stick to drawing with crayons & leave the automotive diagnostics to the people who know But more than likely its the blower motor resistor. Speed 5 is straight through a relay so it bypasses it & speed 4 only uses the last resistor in the pack.

Since its a chevy and it only works On 4 and 5 its the blower motor resistor.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.