How do you recharge air conditioning system on a 1985 Nissan?

Take the car to a quailified automotive air conditioning repair centre and have the system checked for faults. The a/c system combines electrical, mechanical and refrigeration components.Have it leak tested.That model car used R12 when released, the most common gas used today is R134a, most old systems can be retrofitted after faults are repaired. good luck Take the car to a quailified automotive air conditioning repair centre and have the system checked for faults. The a/c system combines electrical, mechanical and refrigeration components.Have it leak tested.That model car used R12 when released, the most common gas used today is R134a, most old systems can be retrofitted after faults are repaired. good luck