Diagnosis And Testing - Hazard Warning Switch
To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, Occupant Classification System (OCS), seat belt tensioner, impact sensor or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the SRS. Failure to follow these instructions may result in accidental airbag deployment.
The hazard switch as well as the hard wired inputs and outputs of the heater or air conditioner and heater control head or the Integrated Center Stack (ICS) switch bank may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information.
- Remove the control head or switch bank from the instrument panel as a unit, but do not disconnect it from the instrument panel wire harness.
- Using a multi-meter, test the continuity between the ground terminal and the hazard switch sense terminal of the control head or switch bank. There should be continuity when the hazard switch push button is in its latched (lowered) position, and no continuity when the push button is in its unlatched (flush) position.
- If the switch fails either of the continuity tests, replace the ineffective control head or switch bank as required.