Checking the power supply

Fig 1: Identifying Ignition ON

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Fig 2: Disconnecting Connector

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• Ignition off
• Disconnect air conditioning (A/C) relay 2/10
• Ignition on.

  Connect a voltmeter between air conditioning (A/C) relay base terminal #1 and ground.

  Fig 3: Identifying Air Conditioning (A/C) Relay Terminals

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 4: Identifying Voltage Display

  Courtesy of VOLVO CARS OF NORTH AMERICA.

The voltmeter should read battery voltage. 

• OK 

  Refer to Checking the signal cable 

• NOT OK 

  Refer to Checking the signal cable