I've 2011 Indica vista drove around 62000 kms. The cooling fan is not working when the temparature goes beyond certain level. The engine was over heated and I was on the long travel also. I've switched on A/C To reduce the engine heat bse when I switched on the ac the cooling fan started running. So I drove the vehicle until I came to my home. What could the reason of this. Why the cooling fan is only operating when switch on ac and not working without ac.