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.
Wide Open Throttle A/C Cut-Off Relay
The WAC relay is normally open (normally closed for Aviator). There is no direct electrical connection between A/C switch or Electronic Air Temperature Control (EATC) module and A/C clutch. On some applications, A/C request signal will be sent to PCM through Standard Corporate Protocol (SCP) BUS (+) and BUS (-) circuits. When A/C is requested, PCM will ensure all other A/C related inputs and engine components are operating correctly before grounding WAC relay output (unground for Aviator), causing voltage to be sent to A/C clutch.
NO RELATED
Use the Manual With the Right Hardware
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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.