Grand Cherokee 4WD L6-4.0L VIN S (1997)
Circuit P7 sends the drivers's heated seat switch signal to the drivers heated seat control module. Circuit P8 sends the passenger heated seat switch
signal to the passenger heated seat control module. In the LOW and HIGH positions, the drivers heated seat switch connects battery voltage on
circuit F71 to circuit P7 (driver's) or P8 (passenger). The LOW and HIGH position detentes have a resistor in series between the detente and
circuit P7 or P8. Internal to the switch, voltage from circuit F71 passes through the resistor to circuit P7 or P8. The voltage level on circuit P7 or
P8 from the switch depends on switch position (LOW or HIGH).
After receiving a signal from its heated seat switch, the heated seat control modules powers the heater grids in the seat. From either control
module, circuit P87 powers the grid in the drivers seat cushion Current flows out of the seat cushion on circuit P88 to the grid on the seat back.
Circuit Z1 from the grid in the seat back supplies ground.
Each heated seat control module monitors seat temperature through a thermistor in each seat. When seat temperature reaches the temperature
selected by the operator through the heated seat switch, the control module stops supplying voltage to the heated seat grids. To maintain selected
seat temperature, the control module cycles the grid ON and OFF.
