Mode Door Feedback Circuit

CAUTION: Do not use a meter with an impedance of less than 10 Meg ohms.

Insert the positive voltmeter probe into terminal H (circuit 903) and the negative probe into terminal 4 (circuit 904). Press mode button and voltage should read 6-8 volts. If no voltage - replace control. If 6-8 volts - check Mode Feedback Potentiometer by inserting the positive voltmeter probe into terminal D (circuit 362) and the negative probe into terminal 11 (circuit 361). Test the voltages in all three positions and compare them to the values below.

Mode Door Position Correct Feedback
Voltage (+/- 0.08V)
Full Vent (A/C) 0.20V
Full Lower (Heater) 2.50V
Full Defrost 4.77V

If voltages are different than those shown above - remove the actuator. With the actuator removed, move the mode door lever to make sure the mode door is not broken or binding. If the mode door moves freely, remove the actuator.
If the controller temperature scale cursors flash for a period of two minutes at every ignition "on" cycle, the controller is indicating a malfunction of the Temperature Door Actuator Circuit.