Blend Door Actuator
Heater Core
WARNING: Carbon monoxide is colorless, odorless and dangerous. If it is necessary to operate the engine with the vehicle in a closed area such as a garage, always use
an exhaust collector to vent the exhaust gases outside the closed area.
1.
NOTE:
Testing of returned heater cores reveals that a large percentage of heater cores are functional and new heater cores were not required. If a heater core leak is suspected, the
heater core must be tested by following the plugged heater core component test before the heater core pressure test. Carry out a system inspection by checking the heater system
thoroughly as follows:
Inspect for evidence of coolant leakage at the heater water hose to heater core attachments. A coolant leak in the heater water hose could follow the heater core tube to the heater
core and appear as a leak in the heater core.
2.
NOTE:
Spring-type clamps are installed as original equipment. Installation and overtightening of non-specification clamps can cause leakage at the heater water hose connection and
damage the heater core.
Check the integrity of the heater water hose clamps.
Heater Core — Plugged
WARNING: The heater core inlet hose will become too hot to handle if the system is working correctly.
1. Check to see that the engine coolant is at the correct level.
2. Start the engine and turn on the heater.
3. 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.
Heater Core — Pressure Test
Ambient Temperature
Resistance
10-20°C (50-68°F)
37,000-58,000 ohms
20-30°C (68-86°F)
24,000-37,000 ohms
30-40°C (86-104°F)
16,000-24,000 ohms
Actuator Pins Approx. Resistance
4 and 5
4,125-6,875 ohms
3 and 5
187-6,523 ohms
3 and 4
187-6,523 ohms
1 and 6
5-100 ohms
Page 43 of 45
2006 Town Car Workshop Manual
12/30/2011
http://www.fordtechservice.dealerconnection.com/pubs/content/~WS6G/~MUS~LEN/19/...
