The tenant has the right, under certain very aggravated circumstances caused by the landlord's neglect, to withhold rent. This can only be done when the landlord fails to comply with an important responsibility, such as
providing a safe and habitable home in compliance with local housing codes.
AC is not required, however if it is in the lease than you are responsible.
He may be able to withold rent.
Before rent is withheld, the tenant must give the landlord seven (7) days written notice of the problem so the landlord can fix it. Even after withholding rent, the tenant should preserve the money and seek court permission to spend part of it to do what the landlord should have done. If the tenant does not preserve the money and seek court assistance, the tenant may be evicted for nonpayment.
Consumer Tip: RIGHTS AND DUTIES OF TENANTS AND LANDLORDS
I hope I helped.