1. Adjust the heater controls to the heater mode, high blower speed.
2. Adjust the temperature control to hot.
3. With the ignition switch on, complete the following steps:

•	Inspect the airflow out of the heater outlet.

•	Inspect the outlet attachment.

Is the airflow high?

--

Go to Step 2

Go to Step 5

Inspect the blower speeds for an airflow change.

Is there an airflow change?

--

Go to Step 3

Go to Step 4

Inspect the following components for proper operation:

Is the repair complete?

--

System OK

--

Refer to HVAC Blower Controls System Check .

Is the repair complete?

--

System OK

--

Inspect the blower speeds for an airflow change.

Is there an airflow change?

--

Go to Step 6

Go to Step 7

Inspect the following components for proper operation:

Do the heater defrost valve and the vacuum actuator operate properly?

--

System OK

--

Refer to HVAC Blower Controls System Check .

Is the repair complete?

--

System OK

--

Is the vent air too warm?

--

Go to Step 2

Go to Step 5

1. Turn the ignition switch ON.
2. Move the temperature control from FULL COLD to FULL HOT.
3. Listen for the temperature valve operation.

Does the temperature valve appear to operate?

--

Go to Step 3

Go to Step 4

1. Verify that the valve operates properly.
2. Inspect the system for the following conditions:

•	A binding actuator

•	A disconnected actuator

Is the inspection complete?

--

System OK

--

Inspect the temperature valve actuator for proper electrical or cable operation. Refer to HVAC Air Delivery System Check .

Is the repair complete?

--

System OK

--

1. Perform a leak test on the system.
2. Inspect the heater outlet attachment.

Does the system case leak?

--

Go to Step 6

--

1. Turn the ignition switch ON.
2. Move the temperature control from FULL COLD to FULL HOT.
3. Listen for the temperature valve operation.

Does the temperature valve appear to operate?

--

Go to Step 7

Go to Step 8

1. Verify that the valve operates properly.
2. Inspect the system for the following conditions:

•	A binding actuator

•	A disconnected actuator

Is the repair complete?

--

System OK

--

Inspect the temperature valve actuator for proper electrical or cable operation. Refer to HVAC Air Delivery System Check .

Is the repair complete?

--

System OK

--

Inspect the system for an objectional defroster bleed.

Does the system demonstrate an objectional defroster bleed?

--

Go to Step 2

System OK

1. Inspect the following components for proper operation:

•	Heater and defrost valve

•	Vacuum actuator

2. Repair the components as needed.

Is the repair complete?

--

System OK

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