Disconnect plug I and plug II from control unit.

Function test of AC button

Battery Hold Down 928 Porsche

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

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) and pin 7 (ground) of plug I

larition on

Reading: battery voltage

Ignition off

Reading: 0 V

Function-testing the individual senders with an ohmmeter.

1.) Temperature sender, cooling water

A resistance of between 1000 ohm and 4000 ohm, depending on engine temperature, should be measurable between pin 1 of plug II and pin 7 of plug I.


2.) Pressure sender, Frigen

Resistance is between 20 ohm and 150 ohm, depending on Frigen pressure.


DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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