C: No Medium or Low Heater Blower Motor Speeds

C1 VOLTAGE BSC

- Start engine, set control to MAX A/C, set heater blower motor switch to MED or LO. If there is no A/C blower motor operation, proceed as follows:

- Turn ignition switch OFF.

- Start engine, set control to MAX A/C and heater blower motor switch at low speed. Check voltage between Pins 2 and 5 of A/C blower motor speed control connector (with connector plugged in). Should be between one and two volts.

- Is the voltage measurement 1-2 volts?

- Yes
Replace A/C blower motor speed control.

- No
Go to C2.

C2 CHECK VOLTAGE AT PINS 2 AND 5

- Verify voltage measurement.

- Does voltage measure zero volts?

- Yes
Go to C3.

- No
Retest. Go to C1.

C3 VOLTAGE CHECK AT LOW SPEED

- Reconnect A/C blower motor speed control connector. With engine running and control set at MAX A/C and heater blower motor switch at low speed, check voltage between Pin 6 of control module and ground. Should be one to two volts.

- Is the voltage measurement 1 to 2 volts?

- Yes
Service circuit between ATC module and A/C blower motor speed control (752 Y/R) or circuit between EATC module and A/C blower motor speed control.

- No
Go to C4.

C4 CHECK VOLTAGE AT PINS 6

- Verify voltage measurement.

- Does voltage measure zero volts?

- Yes
Replace EATC or ATC module.

- No
Retest. Go to C3.