928 S4 V8-4957cc 5.0L (1987)
Control Assembly: Testing and Inspection
Checking Operating Switch
CHECKING OPERATING SWITCH
Note: With operating switch removed and all connections made, use a voltmeter to test voltages at the 15- pole plug.
1. Switch on ignition.
2. Connect voltmeter to terminal 1 (plus) and terminal 4 (minus).
Air-distribution slide at bottom and bottom/top.
Reading: Battery voltage.
3. Connect voltmeter to terminal 2 and terminal 4.
Air-distribution slide at off, center and bottom.
Reading: Battery voltage
4. Connect voltmeter to terminal 3 and terminal 4.
Switch on position lights.
Reading: Battery voltage.
5. Connect voltmeter to terminal 5 and terminal 4.
Air-distribution slide at centre, bottom, bottom/top, top and defrost.
Reading: Battery voltage.
If no voltage is registered, check whether fresh-air blower relay switches. If the fresh-air blower relay does not switch, test the signal at terminal
86. Connect voltmeter to terminal 15 and terminal 4 of operating switch. Air-distribution slide at the same positions.
Reading: Battery voltage.
6. Connect voltmeter to terminal 7 and terminal 4.
Air-distribution slide at center, bottom, bottom/top and defrost.
Switch on auxiliary air conditioner.
Reading: Battery voltage
If no voltage is registered, check air-conditioner switch.
7. Connect voltmeter to terminal 6 and terminal 4.
Air-distribution slide at center, bottom, bottom/top and top.
Switch on auxiliary air conditioner.
Reading: Battery voltage.
8. Connect voltmeter to terminal 8 and terminal 4.
Air-distribution slide to center, bottom, bottom/top and top.
Temperature regulator slide at 18.
Reading: Battery voltage
Move temperature regulator slide to 27. The setting motor moves toward heating. At 10%, the voltage in interrupted.
9. Connect voltmeter to terminal 9 and terminal 4.
Air-distribution slide at off.
Reading: Battery voltage
10. Leave voltmeter connected to terminal 9 and terminal 4.
Air-distribution slide at center, bottom, bottom/top and top.
Switch on air conditioner.
Temperature regulator slide at 18.
Display: Battery voltage.
Set temperature regulator slide to 27. The setting motor moves toward heating. Voltage is interrupted at 10%.
11. Connect voltmeter to terminal 10 and terminal 4.
Reading: Battery voltage
12. Connect voltmeter to terminal 11 and terminal 4.
Air-distribution slide at defrost.
Reading: Battery voltage