not a real big deal. just annoying more than anything. does it with both heater and the AC

My a/c cuts on and off when the switch is in the off position sometimes. I just would like to know what possible problem is, how much the possible cost to repair and why it occurred.

I was waiting for my sister to come out of the store. I did not have the A/C or Heater on at all and all of a sudden the heater starts blowing then went off, about a min. later it did it again. then again. I was thinking that it may be a way the car keeps the engine from getting too hot but I used the sync thing in the car that said the temp was OK. I hope this is not going to lead to a bigger issue.