Section 446 (Defogger System): Inspection

1. Connect the positive (+) lead from the voltmeter to terminal of body ECU No. 1 connector and negative (-) lead to body ground.
   Fig 1: Connecting Voltmeter Positive Lead To Body ECU No. 1 Connector Terminal 6 & Negative Lead To Body Ground

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2. When the switch is OFF, the voltage should be approx. 12V.
3. Turn the defogger switch ON and check that the indicator lights up and that the voltage is less than 1 V.
4. After 15 minutes, check that the switch is OFF and the voltage is approx. 12 V.

If operation is not as specified, replace the switch.

Fig 2: Checking Indicator Lights Up

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Disconnect the connector from the A/C control assembly and inspect the connector on wire harness side, as shown in TESTER CONNECTION SPECIFIED CONDITION TABLE .

Fig 3: Inspecting Defogger Switch (In A/C Control Assembly) Circuit

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If the circuit is not as specified, replace the switch.

Fig 4: Inspecting Defogger Relay Continuity

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If continuity is not as specified, replace the relay.

Fig 5: Inspecting Mirror Defogger Relay Continuity

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If continuity is not as specified, replace the relay.

1. Turn the ignition switch ON.
2. Turn the defogger switch ON.
3. Inspect the voltage at the center of each heat wire, as shown in Fig 7.
   DEFOGGER WIRE
   
   

   Voltage	Criteria
   Approx. 5 V	Okay (No break in wire)
   Approx. 10 V or 0 V	Broken wire

   Fig 7: Inspecting Voltage At Center Of Each Heat Wire

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   HINT:

   If there is approximately 10 V, the wire is broken between the center of the wire and the positive (+) end. If there is no voltage, the wire is broken between the center of the wire and ground.

4. Place the voltmeter positive (+) lead against the defogger wire on the battery side.
5. Place the voltmeter negative (-) lead with the foil strip against the wire on the ground side.
6. Slide the positive (+) lead from battery to ground side.
7. The point where the voltmeter deflects from several V to zero V is the place where the defogger wire is broken.
   Fig 8: Inspecting Defoggers Wire

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HINT:

If the heat wire is not broken, the voltmeter indicates 0 V at the positive (+) end of the heat wire but gradually increases to about 12 V as the meter probe moves to the other end.

1. Clean the broken wire tips with grease, wax and silicone remover.
2. Place the masking tape along both sides of the wire for repair.
3. Thoroughly mix the repair agent (Dupont paste No. 4817).
   Fig 9: Placing Masking Tape Along Both Sides Of Wire For Repair

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4. Using a fine tip brush, apply a small amount of the agent to the wire.
   Fig 10: Applying Small Amount Of Agent To Wire Using Fine Tip Brush

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5. After a few minutes, remove the masking tape.
6. Do not repair the defogger wire for at least 24 hours.

1. Connect the positive (+) lead from the battery to terminal and the negative (-) lead to terminal 8.
2. Check that the mirror becomes warm.

HINT:

It will take a short time for the mirror to become warm.

Fig 11: Inspecting Mirror Defogger Operation (W/Mirror Heater (W/O Driving Position Memory))

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1. Connect the positive (+) lead from the battery to terminal and the negative (-) lead to terminal 13.
2. Check that the mirror becomes warm.

HINT:

It will take a short time for the mirror to become warm.

Fig 12: Inspecting Mirror Defogger Operation (W/Mirror Heater (W/Driving Position))

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