2. INSPECT RELAY OPERATION (a) Apply battery voltage across terminals 1 and 3. (b) Check that there is continuity between terminals 4 and 5. (c) Check that there is no continuity between terminals 2 and 4. If operation is not as specified, replace the relay. Heater Blower Resistor INSPECTION OF HEATER BLOWER RESISTOR INSPECT RESISTOR CONTINUITY Check that there is continuity between terminals 1 and 3. If there is no continuity, replace the resistor. Heater Control ADJUSTMENT OF HEATER CONTROL SET AIR INLET DAMPER Set the air inlet damper and control lever to "FRESH". SET MODE SELECTOR DAMPER Set the mode selector damper and control lever to "VENT". SET BALANCE DAMPER Set the balance damper and control lever to the center position. TEST CONTROL CABLE OPERATION Move the control levers left and right and check for stiffness and binding through full range of the levers.