Rear Blower Rear Control Switch Inoperative In One Or More Speeds

NOTE: After making any repairs, perform BODY VERIFICATION TEST under VERIFICATION TESTS.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Turn the ignition off. Disconnect the Rear Blower Rear Control Switch C1 harness connector. See Figure. Turn the ignition on. Turn the Power switch on the A/C-Heater Control Module on. Using a 12-volt test light connected to ground, back probe each of the Rear Blower Motor Driver circuits (Low, Medium, and High). If the test light illuminates brightly on each circuit, go to the next step. If the test light does not illuminate brightly on each circuit, repair all Rear Blower Motor Driver circuits that failed to illuminate the test light brightly for an open.
Turn the Power switch on the A/C-Heater Control Module off. Turn the ignition off. Make sure that the Rear Blower Rear Control C1 harness connector is connected to the Rear Blower Rear Control Switch. Using a jumper wire connected to ground, back probe the Rear Blower Motor Front Control Feed circuit in the Rear Blower Rear Control Switch C1 harness connector. Turn the ignition on. Turn the Power switch on the A/C-Heater Control Module on. Turn the Blower switch on the Rear Blower Rear Control Switch to each speed position. If the rear blower runs in all speeds, go to the next step. If the rear blower does not run in all speeds, replace the Rear Blower Rear Control Switch. See HVAC CONTROLS (REAR) under REMOVAL & INSTALLATION in MANUAL A/C-HEATER SYSTEMS article in HVAC.
Turn the ignition off. Disconnect the Rear Blower Front Control Switch harness connector. See Figure. Disconnect the Rear Blower Rear Control Switch C1 harness connector. See Figure. Measure the resistance of the Rear Blower Motor Front Control Feed circuit between the Rear Blower Front Control Switch harness connector and the Rear Blower Rear Control Switch C1 harness connector. If the resistance is less than 5 ohms, replace the A/C-Heater Control Module. See A/C-HEATER CONTROL PANEL under REMOVAL & INSTALLATION. If the resistance is more than 5 ohms, repair the Rear Blower Motor Front Control Feed circuit for an open.