Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2006 Honda S2000 L4-2.2LFACTORY OEM SERVICE PROCEDURE
Function Test
Function Test
NOTE: Be careful not to scratch or damage the defogger wires with the tester probe.
1. Check for voltage between the positive terminal (A) and body ground with the ignition switch and defogger switch ON. There should be battery voltage.
- If there is no voltage, check for:
- Faulty defogger relay.
- Faulty defogger change relay ('02-07 models).
- Faulty diode ('02-07 models).
- An open in the wire.
- If there is battery voltage, go to step 2.
2. Check for continuity between the negative terminal (B) and body ground.
If there is no continuity, check for an open in the defogger ground wire.
3. Touch the voltmeter positive probe to the halfway point of each defogger wire, and the negative probe to the negative terminal.
There should be approximately 6 V with the ignition switch and the defogger switch ON.
- If the voltage is as specified, the defogger wire is OK.
- If the voltage is not as specified, repair the defogger wire.
- If it is more than 6 V, there is a break in the negative half of the wire.
- If it is less than 6 V, there is a break in the positive half of the wire.
NOTE: Be careful not to scratch or damage the defogger wires with the tester probe.
1. Check for voltage between the positive terminal (A) and body ground with the ignition switch and defogger switch ON. There should be battery voltage.
- If there is no voltage, check for:
- Faulty defogger relay.
- Faulty defogger change relay ('02-07 models).
- Faulty diode ('02-07 models).
- An open in the wire.
- If there is battery voltage, go to step 2.
2. Check for continuity between the negative terminal (B) and body ground.
If there is no continuity, check for an open in the defogger ground wire.
3. Touch the voltmeter positive probe to the halfway point of each defogger wire, and the negative probe to the negative terminal.
There should be approximately 6 V with the ignition switch and the defogger switch ON.
- If the voltage is as specified, the defogger wire is OK.
- If the voltage is not as specified, repair the defogger wire.
- If it is more than 6 V, there is a break in the negative half of the wire.
- If it is less than 6 V, there is a break in the positive half of the wire.
Factory Service Tools
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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.
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