Window Defogger System: Inspection

w/ Mirror heater: INSPECT OUTER REAR VIEW MIRROR ASSY LH
1. Apply battery voltage and check operation of the mirror heater.
OK:

Fig 1: Inspecting Outer Rear View Mirror Assy LH
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the result is not as specified, replace the mirror assy.

Fig 2: Measurement Condition And Specified Condition (1 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
w/ Mirror heater: INSPECT OUTER REAR VIEW MIRROR ASSY RH
1. Apply battery voltage and check operation of the mirror heater.
  OK:
  
  Fig 3: Inspecting Outer Rear View Mirror Assy RH
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If the result is not as specified, replace the mirror assy.
Fig 4: Measurement Condition And Specified Condition (2 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT BACK WINDOW (DEFOGGER WIRE)

NOTE:

When cleaning the glass, wipe the glass along the wire using a soft, dry cloth. Take care not to damage the wires.
Do not use detergents or glass cleaners that have abrasive ingredients.
When measuring voltage, wrap a piece of tin foil around the tip of the negative tester probe and press the foil against the wire with your finger, as shown in the illustration.

Fig 5: Identifying Tester Probe On Tin Foil

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Turn the ignition switch ON.
Turn the defogger switch ON.

Measure the voltage at the center of each defogger wire as shown in the illustration.

Standard:

VOLTAGE AND CRITERIA SPECIFICATION

Voltage	Criteria
Approx. 5 V	Wire is not broken
Approx. 10 or 0 V	Wire is broken

Fig 6: Measuring The Voltage At The Center Of Each Defogger Wire

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

If there is approximately 10 V, the wire may be faulty between the center of the wire and the wire end on the battery side. If there is no voltage, the wire may be faulty between the center of the wire and the wire end on the ground side.

Place the voltmeter's positive (+) lead against the defogger wire on the battery side.
Place the voltmeter's negative (-) lead with the foil strip against the wire on the ground side.

Fig 7: Placing The Voltmeter'S Positive (+) Lead Against The Defogger Wire On The Battery Side
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Slide the positive (+) lead from the battery side to the ground side.
The point where the voltage jumps from approximately 10 V to 0 V is where the defogger wire is broken.
HINT:

If the defogger wire is not broken, the voltmeter indicates 0 V at the positive (+) end of the defogger wire and gradually increases to approximately 12 V as the meter probe moves to the other end.
If necessary, repair the defogger wire.
1. Clean the broken wire tips with grease, wax and silicone remover.
2. Place the masking tape along both sides of the wire.
3. Thoroughly mix the repair agent (Dupont paste No. 4817 or equivalent).
  
  Fig 8: Placing The Masking Tape Along Both Sides Of The Wire
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Using a fine tip brush, apply a small amount of the agent to the wire.
5. After a few minutes, remove the masking tape.

NOTE: Do not repair the defogger wire again for at least 24 hours.

Fig 9: Applying A Small Amount Of The Agent To The Wire

INSPECT RELAY (Marking: DEF)

Remove the DEF relay from the engine room R/B.
Measure the resistance of the relay.

Standard:

TESTER CONDITION AND SPECIFIED CONDITION

Tester Condition	Specified Condition
3-4	Below 1 Ω
3-5	10 kΩ or higher
3-5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

If the result is not as specified, replace the relay.

Fig 10: Measuring The Resistance Of DEF Relay From The Engine Room R/B