I have a similar problem with a 2001 Grand Caravan Sport - Passenger side blows cold air at all settings. So far research has pointed toward a bad actuator and/or blockage of some type at or in the heater box. Haven't yet dug into it to confirm but I'll post once I have.
If equipped, it is under the dash on the passenger side.
Disconnect the send and return lines to the heater core and connect them together
It is over the passenger side strut tower, accessible from under the hood.
The Heater Core is located passenger side next to the firewall, inside the vehicle.The Heater Core is located passenger side next to the firewall, inside the vehicle.
Sounds like your heater core has gone bad.
It sounds like the heater core is leaking. Check for the smell of antifreeze and that will confirm the bad heater core.
The heater housing is behind the dash on the passenger side.
The heater core is behind the dash the passenger side of the car.
The heater would not be working on a 1990 Dodge Grand Caravan if the heater core is damaged or blocked. Hot coolant from the engine must flow through the core to allow hot air to pass into the cabin.
Very hard.............. You will need to discharge the a/c system, pull back the dash and remove the complete a/c and heating box to remove the heater core.........
The heater coil is leaking. Water from the cooling system runs through the heater coil to heat the passenger compartment. Antifreeze is corrosive, some heater coils are thin.
it's on the outside on the passenger side.near the heater core hoses.