Do you need to disconnect the AC replace heater core on a 1996 Honda Passport?

Yes, you will likely need to disconnect the AC system to replace the heater core in a 1996 Honda Passport. The heater core is located behind the dash, and often very close to or even integrated with the AC evaporator core. Disconnecting the AC system (at a minimum, the hoses) will give you better access and prevent accidental damage to the AC components during the heater core replacement. While it's *possible* to do it without disconnecting, it's significantly more difficult and risky. Properly disconnecting and reconnecting the AC system will also require vacuuming and refilling the system to prevent leaks and ensure proper function.