INSPECT CENTER CLUSTER MODULE SWITCH
1. Check operation of the defogger timer.
  1. Connect the battery's positive (+) lead to terminal 3 and the negative (-) lead to terminal 4.
  2. Connect the battery's positive (+) lead to terminal 4 through a 1.4 W test bulb.
  3. Push the rear window defogger switch ON, check that the switch and the test bulb illuminate for 12 to 18 minutes, and then they go off.
    If the result is not as specified, replace the switch.
    
    Fig 1: Connecting Battery's Positive (+) Lead To Terminal 3 & Negative (-) Lead To Terminal 4
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT BACK DOOR GLASS (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 tinfoil around the tip of the negative probe and press the foil against the wire with your finger, as shown in the illustration

Fig 2: Wrapping Piece Of Tinfoil Around Tip Of Negative Probe
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 3: Measuring Voltage At 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 positive (+) lead against the defogger wire on the battery side.
Place the voltmeter negative (-) lead with the foil strip against the wire on the ground side.

Fig 4: Placing Voltmeter Positive (+) Lead Against Defogger Wire On 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 drops 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 but gradually increases to about 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).
  
  Fig 5: Placing Masking Tape Along Both Sides Of 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.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Window Defogger System: Inspection

Use the Manual With the Right Hardware

When to See a Mechanic

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