Checking the power supply to the brake valve

Fig 1: Identifying Ignition ON

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Disconnecting Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

• Ignition off.
• Disconnect the brake valve.
• Selector switch connected.
• Ignition on.
• Selector switch in the OFF position.

  Connect a voltmeter between brake valve connector terminal #1 and ground.

  Fig 3: Identifying Connector Terminals

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

  Courtesy of VOLVO CARS OF NORTH AMERICA.

The voltmeter should read approximately 0 V. 

• OK 

  Refer to Checking the cable between the selector switch and the brake valve 

• NOT OK 

  Refer to Checking for a short-circuit