Repairs could depend on the extent of repair and whether it is caused by tenant's negligence or abuse of said air-cond. It also depends on whether one is renting the entire place or a room. If it's a student, most landlords do not expect the students to pay for the repairs or maintenance. For families, they could take it on themselves, or some landlords would just cover it as part of the "fully-furnished" rental.
All said and done, it all depends on what is outlined in the tenancy agreement or agreed beforehand.
For more on tenant's rights and tenancy agreement, take a look at this: https://www.propertyguru.com.my/property-guides/exploring-tenant-rights-and-tenancy-agreement-in-malaysia-23640
Hope that it all works out well.