K 2500 Truck 4WD V8-454 7.4L (1990)
CAUTION: Do not use a meter with an impedance of less than 10 Meg ohms.
Insert 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