Operation CHARM: Car repair manuals for everyone.

Contact Resistance and Oxidation



Contact resistance and oxidation







In theory, the resistance across contacts, leads and terminals should be 0 [ohm]. However, there is always some resistance due to terminal oxidation.
If resistance is too great there will be function problems.
The magnitude of the resistance before it causes a malfunction depends on the circuit load. A guideline would be a few ohms.







NOTE: Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) or combined instrument panel connectors.


- Ignition off
- Disconnect the battery negative terminal
- Use compressed air to clean the disconnected connector
- Apply rust solvent spray 1161422 to the disconnected connectors
- Blow clean using compressed air.












NOTE: Do not fill the protective cover with grease.

- Press grease, P/N 1161417-9, into the terminals directly from the tube
- Check that all the cavities in the connectors are filled
- Use a loose male pin to ensure that contact in sockets is good. The pin should remain in position when pulled gently.