HOSE 0856997 - Caterpillar

Functions
Illustration 1 g01131704
The microcomputer sends signals to the DC motor. This changes the discharge positions in order to control the damper position for the following settings:
Face
B/L
Foot
Foot/DefChecking and Maintenance
Illustration 2 g01131790
(R) Resistance (kOhms) (T) Temperature
Table 1
Resistance (kOhms) between terminal (2) and terminal (3) in certain damper settings    
Damper setting     Resistance value (kOhms)    
Face     1.2    
B/L     3.1    
Foot     4.1    
Foot/Def     5.4    
Def     5.9    If any of the values deviate from the chart above, replace the motor.When the resistances have been checked, check the continuity at normal voltage. Adjust the damper setting to Face. Voltage should be 24 V at terminal 21. When you move from Face to Def (terminal 22) the voltage should read 0 V. Next, set the damper to Def (terminal 22). The voltage should be 0 V. Move the damper to Face (terminal 21). The voltage should be 24 V.