Test E: Blower Motor Always On

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For circuit reference, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

NOTE: DEFINITION: The blower motor is ON while the HVAC control is in the OFF position.

If diagnostic system check was not performed, go to If diagnostic system check was not performed, go to DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. If diagnostic system check was performed, go to next step. If diagnostic system check was performed, go to next step.
Turn ignition on. Turn off HVAC controls. If blower motor is off, problem is intermittent. If blower motor is on, go to next step.
Using scan tool, observe DESIRED BLOWER MTR SPEED parameter in heating and air conditioning data list. If scan tool indicates desired blower motor speed parameter is near zero counts, go to next step. If parameter is not near zero counts, go to step 7.
Disconnect HVAC control module. If blower motor continues to operate, go to next step. If blower motor does not continue to operate, go to step 7.
Check blower motor housing and blower motor control circuit in blower motor harness for a short to ground. Repair wiring as necessary. If wiring is okay, go to next step.
Check for poor connections at harness connector of blower motor control processor. Repair connector as necessary. If connector is okay, go to step 8.
Check for poor connections at harness connector of HVAC control module. Repair connection as necessary. If connection is okay, go to step 9.
Replace blower motor control processor. See BLOWER MOTOR CONTROL MODULE PROCESSOR under REMOVAL & INSTALLATION. After repairs are complete, go to step 10.
Replace HVAC control module. See HVAC CONTROL MODULE under REMOVAL & INSTALLATION. After repairs are complete, go to next step.
Operate the system in order to verify the repair. Did you correct the condition? If so, system is okay. If not, go to step 2.