Porsche 928 - WORKSHOP MANUAL 1977 Workshop Manual page 438

87
Air Conditioner 928
CHECKING OPERATING SWITCH
Note:
With operating switch removed and
all connections made, use a volt-
meter to test voltages at the 15-
pole plug.
l.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 ter-
minal 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.
a
87 - 110
Checking Operating Switch
Printed in Germany