A/C Signal: Testing and Inspection

1998 Mazda 626 LX L4-2.0L DOHCSECTION Testing and Inspection




1. Start the engine and let it idle.
2. Turn the A/C switch and the fan switch ON.
3. Check if the operation sound of the A/C compressor electromagnetic clutch is heard. (A/C compressor starts to work.)
4. Fully open the throttle valve. Check if the operation sound the A/C compressor magnetic clutch is heard. (A/C compressor stops to work.) Then, 3-6 seconds after, check if the operation sound of the A/C compressor electromagnetic clutch is heard.
5. Turn the A/C switch and the fan switch OFF.
6. If the operation sound is not heard, do as follows.
(1) Connect a jumper wire between both terminals of A/C pressure switch connector.
(2) Turn the ignition switch ON.
(3) Turn the A/C switch and the fan switch ON. Verify that operation sound is heard from A/C relay.
(4) If the operation sound is heard, check the following PID using NGS tester.
- TP V PID.
(5) If the operation sound is not heard, check the following.
- A/C relay.
- Open or short to ground circuit in wiring harnesses and connectors (Main relay-A/C relay-PCM terminal 69)
- A/C related parts.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.