Porsche 928 Workshop Manual page 311

19
Engine - Cooling
928
TROUBLESHOOTING
Disconnect plug
control unit.
I and plug I I from
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1.) Test voltage supply
Connect voltmeter to pin 2
(plus) and pin 7 (minus) of
plug I
Reading: battery voltage
2.) Connect voltmeter to pin 4
(plus) ard pin 7 (ground) of
plug I
Igrition on
Reading: battery voltage
Ignition off
Reading: 0 V
Function test of AC button
Connect voltmeter to pin 7 (ground)
of plug I and pin 5 (plus) of plug
II
Ignition on
Press AC button
Set the air-distribution slide
switch to up/down.
Reading: battery voltage
19 - 22
Troubleshooting XX,1988 - Printed in Germany