Heater valve location

Hi Don,

Heater valve is located engine compartment, right hand rear side of inner fender.
As a first step check if vacuum present on the valve when heater switch is on, then use hand vacuum apply vacuum on heater valve check if its actuating and maintaining the applied vacuum.

Remove or Disconnect
1. Engine coolant.
2. Hose clamps at heater water valve.
- Loosen the clamps enough to slide the clamps away from the fittings on the valve.
3. Hoses from valve.
4. Vacuum line from valve.
5. Valve.

Install or Connect
1. Vacuum line to valve.
2. Hoses to valve.
3. Clamps to hoses.
- Slide clamps to previous location beyond retaining bead on water valve fitting.
4. Engine coolant.

If your system does not have valve, Here's the description of your unit:

Description: System is a blend-air type. Outside air is heated and then mixed with cooler outside air to attain desired temperature. System consists of a blower and an air inlet assembly, heater air distributor assembly and heater control panel. Blower, air inlet assembly and heater hoses are located on the engine side of dash panel while heater core and distributor duct are on passenger side. System has no heater control valve. Coolant circulation keeps heater core hot at all times. Operation of blower motor is controlled by the fan switch. The motor is connected in series with the fan switch and blower resistor assembly.
-trouble shooting.
Heater Core " Plugged
WARNING: The heater core inlet hose will become too hot to handle if the system is working correctly.
Check to see that the engine coolant is at the correct level.
Start the engine and turn on the heater.
When the engine coolant reaches operating temperature, feel the heater core inlet and outlet hose to see if they are hot.
If the inlet hose is not hot:
the thermostat is not working correctly.
If the outlet hose is not hot:
the heater core may have an air pocket.
The heater core may be restricted or plugged.
If both are hot, the temperature blend door in the heater plenum may be broken or stuck.
You might also try a core back flush. Buy a flush kit, install the Tee in the return line(to pump), and disconnect the supply hose, now back flush until water runs clear, I usually get two Tees, and flush both ways, a heater core is not linear, water path is much like a honeycomb. Hard to flush, radiator repair shops use a pressure gun to clear them, but can save the time involved in replacing harder installations. If your core is easily accessible, changing it is the best answer!