On the firewall behind the intake. PITA to get to or even see for that matter
mercury villager heater core 2001
Near the firewall behind the engine, or under the dash near the heater core.
replace the dash control unit
On the bottom of the heater/AC housing under the dash.
The evaporator is in the A/C heater box under the dash.
Inside the dashboard at the right.
I would not recommend that you try. A block heater is preferred.
Not all models had a heater control valve. If it has one it's either right in front of the firewall by where the heater hoses go in, or else under the dash near the heater core.
Open the glove compartment and remove it. Disconnect the electrical connector and the three mounting screws. Remove motor.
If it is defective it will need to be replaced.
There would only be a rear heater core if there was a rear heater, which I don't believe was an option.
It should be located on the evaporator case.