Checking the signal cable

• Remove glove compartment.
• Disconnect air conditioning (A/C) relay (2/22).
  Fig 1: Ohmmeter

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  • Connect an ohmmeter between relay base terminal 4 and #40 (#B40) on the breakout box.

The ohmmeter should read approximately 0 Ω. 

• OK 

  Refer to Checking the power supply to relay base terminal 1 

• NOT OK 

  Refer to Checking for an open-circuit