Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

A/C Signal: 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 A/C compressor magnetic clutch operation sound is heard. (A/C compressor stops to work.) Then, 3 - 6 seconds after, check if the operational sound of the A/C compressor electromagnetic clutch is heard.
5. Turn the A/C switch and the fan switch OFF.
6. If the sound is not heard:
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 sound is heard from A/C relay.
4. If the operation sound is heard, check the TP V PID.
- 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.