Why is my air conditioning only kicking on when the vehicle is accelerated?

The fan blows fine in any setting the air is just not cold because the compressor is not kicking in until its rev'd up. Think it may be the clutch pulley but was just trying to see other peoples thoughts first before I spent the money on it. However thank you for the answer.

Have you tested your compressor clutch relay or condenser fan relay? When my condenser fan began to go out I noticed that these same symptoms and soon after the compressor began screeching.

Thank you I'll look into those and get back to you. Thanks for the ideas.