Rear window defroster (Honda Civic 5)

Checking the input signal, switch (with timer)

Caution: When pulling out the switch, be careful not to damage the rear window defogger switch or the center console.

Note: Before starting the test, check if fuse #16 (7.5A) in the under-panel fuse and relay box is blown.

1. Pull the switch out of the center panel.

2. Disconnect the 5K connector from the switch.

3. Turn the ignition switch to ON(II) and check the voltage between the BLK/BLU (+) and BLK (-) terminals. There should be battery voltage.

• If there is no voltage, check for a break in the BLK/BLU wire.
• If battery voltage is present, proceed to step 4.

4. Connect the connecting wire between the BLK/BLU and BLU/YEL terminals

5. Turn the ignition switch ON(II) and check if the rear window heater works, if it works, replace the heater switch.

Checking the switch (without timer)

Caution: When pulling out the switch, be careful not to damage the rear window defogger switch or the center console.

1. Pull the switch out of the center panel.

2. Check the conductivity between the contacts in each switch position, according to the table.

Functional check

Caution: Be careful not to damage or scratch the heater wires with the tester probe.

1. Check the voltage between the positive terminal and the housing with the ignition switch and the heater switch ON.

There should be battery voltage.

• If there is no voltage, check:

-The heater relay is faulty.

-The heater switch is faulty.

-Break in BLK/BLU wire.

• If battery voltage is present, proceed to step 2.

2. Check the conductivity between the negative contact and the body.



If there is no continuity, check for a break in the heater ground wire.

3. Connect the positive probe of the voltmeter to the point in the middle of each heater wire and the negative probe to the negative terminal.

There should be approximately 6V with the ignition switch on and the heater switch ON.

• If the voltage is within specification, the heater wire is OK.
• If the voltage is out of specification, repair the heater wire.
• If more than 6V, there is a break in the negative half of the wire.
• If less than 6V, there is a break in the positive half of the wire.

Repair of heater conductors

Note: Effective repair is only possible if the damaged portion of the wire is less than one inch.

1. Lightly brush the area around the damaged part with wool, then clean with alcohol.

2. Carefully cover the damaged part of the heater wire with cellophane tape at the top and bottom.



3. Using a small brush, apply a thick coat of 1/8-inch silver conductive paint to both sides of the gap. Allow 30 minutes to dry.

Note: Stir paint thoroughly before use.

4. Check the conductivity in the repaired conductor.



5. Apply a second coat of paint in the same way* Allow the paint to dry for 3 hours, then remove the tape.