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.
Test Description
Numbers below refer to the numbers in the Diagnostic Procedure:
- 3
This test determines is problem is with refrigerant system. If switch is open, A/C pressure gauges will be used to determine if pressure switch is faulty or if the system is partially discharged or empty. - 4
Although the normal complaint will be A/C clutch fails to engage, it is possible for a short circuit to cause A/C clutch to run when A/C has not been selected. This step tests for that condition. - 7
There is an extremely low probability that both relays will fail at the same time, so substitution process is one way to check A/C Thermostat relay. Use a known good relay to do a substitution check.
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.
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