Chart 7 Rear Blower Inoperative

CIRCUIT DESCRIPTION

Power from CONSOLE FUSE is applied to the blower motor and ground through the switch. The blower speed is controlled by varying the circuit amperage using a series of three resistors contained in a module. The heater and A/C programmer receives a feedback voltage signal, but this has no effect on rear blower operation.

TEST DESCRIPTION

Numbers below refer to circled numbers on the diagnostic chart.

1. If CKT 52, CKT 850 and the HI position of the switch have continuity then the reading will be nearly zero. As slower speeds are selected, the blower motor ground path passes through more series resistors in the module and results in increasing voltages at 5345. Battery voltage should be read in OFF.
2. If a resistor in the module is open, all cavities beyond that point will also be open. If cavity E operates blower, then the fault is in the switch or wiring to the switch.