Manual:HUMMER Hummer H3 Base 2010Page:23235 / 37523



Circuit/System Testing — 2010 Hummer H3 Base, Automatic Service Manual

Circuit/System Testing

  1. Ignition OFF, disconnect the HVAC relay.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 86 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  3. Install a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
  4. Command the blower motor ON and OFF with the scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
    • If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the HVAC relay.