RPM Surge when A/C is on

[Cisc0]

Greetings all,

Hopefully someone can shed some light on this issue. While the vehicle is stopped at light or parked and A/C is on, the RPM needle surges up to between the 1 and 2. Feels like if I was touching the throttle. If I turn A/C off, it stops. All this while the A/C blows out cool air, not hot, not cold.

I will have it diagnosed soon, but just wondering what the culprit could be.

Thanks in advance for replies and help.