Symptom:
*BLOWER SPEED DOES NOT CORRESPOND WITH CONTROL
SETTING - MTC
POSSIBLE CAUSES
BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO GROUND
BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO VOLTAGE
BLOWER MOTOR DRIVER CIRCUITS SHORTED TOGETHER
A/C HEATER CONTROL
BLOWER MOTOR DRIVER CIRCUIT(S) OPEN
BLOWER MOTOR RESISTOR BLOCK
TEST
ACTION
APPLICABILITY
1
Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor Resistor Block C1 harness connector.
Measure the resistance between ground and each of the Blower Motor Driver circuits.
Is the resistance below 10K ohms on any of the circuits?
All
Yes
→ Repair all Blower Motor Driver circuits with a resistance below
10K ohms for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No
→ Go To 2
2
Turn the ignition off.
Ensure that the Blower Motor Resistor Block C1 harness connector is connected to
the Blower Motor Resistor Block.
Disconnect the A/C Heater Control C2 harness connector.
Turn the ignition on.
Press the A/C Heater Control’s power switch on.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Using a 12-volt test light connected to ground, back probe each of the Blower Motor
Driver circuits (cavities 2, 3, 9, 10).
Does the test light illuminate brightly on each circuit?
All
Yes
→ Go To 3
No
→ Go To 5
3
Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor Resistor Block C1 harness connector.
Turn the ignition on.
Press the A/C Heater Control’s power switch on.
Measure the voltage of each of the Blower Motor Driver circuits (cavities 2, 3, 9, 10)
in the A/C Heater Control C2 harness connector.
Is there any voltage present?
All
Yes
→ Repair all Blower Motor Driver circuits with voltage present for a
short to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No
→ Go To 4
637
HEATING & A/C