Wiring Checking

Tools required:

LED tester V.A.G. 1527
Test box V.A.G. 1598
Test adapter 1598/8
Applicable wiring diagram

NOTE:

The socket identifications on the test box V.A.G. 1598 are the same as the contact identification on the instrument cluster.
All wires of the instrument cluster wiring harness between instrument cluster and relay panel were changed to all white wires of 0.35 mm² . These wires may still be listed as colored in the wiring diagram. If the instrument cluster is faulty it must be replaced. Do not attempt repairs.

Troubleshooting preparations

Switch off ignition.
Remove instrument cluster. See INSTRUMENT CLUSTER, REMOVING AND INSTALLING .
Using adapter wire 1598/8, connect test box V.A.G. 1598 to 28-pin connector, terminal 1, on instrument cluster and disconnected 28-pin connector on wiring harness.
Do not connect instrument cluster to test box V.A.G. 1598, but leave the adapter connection open.
Set multimeter Fluke 83 to 20 V DC range.
If you do not obtain the test values as listed in Warning Lights In Instrument Cluster Test table, check wiring as per applicable wiring diagram.
if you obtain the test values as listed in the table, the wiring to the instrument cluster is OK. In such case replace the instrument cluster.

Warning Lights In Instrument Cluster Test

Test Step	Check wiring for:	Test conditions and additional operations	Specified values Test results
1	Generator Warning Light (K2)	Connect multimeter to sockets 16 and 3 of test box V.A.G. 1598. Switch on ignition	Approximately 0 V
2	Oil pressure Warning Light (K3)	Connect multimeter to sockets 8 and 13 of test box V.A.G. 1598. Switch on ignition. Start engine.	Approximately 0 V Approximately battery voltage
3	Life Turn Signal indicator (K65)	Switch on ignition. Switch on left turn signal. Connect LED tester V.A.G. 1527 to sockets 22 and 3 of test box V.A.G. 1598.	LED tester blinks
4	Right Turn Signal Indicator Light (K94)	Switch on ignition. Switch on right turn signal. Connect LED tester V.A.G. 1527 to sockets 24 and 3 of test box V.A.G. 1598.	LED tester blinks
5	Instrument Cluster Light (L10) and Digital Display Light (L75)	Switch on Light Switch (E1). Operate Instrument Cluster Light Dimmer Switch (E20). Connect multimeter to sockets 12 and 3 of test box V.A.G. 1598.	Approximately 2.0 V to battery voltage, depending on position of Instrument Cluster Light Dimmer Switch (E20)
6	Headlight high beam indicator light (K1)	Switch on high beam. Connect multimeter to sockets 25 and 3 of test box V.A.G. 1598.	Approximately battery voltage
7	Brake and Parking brake Warning Light (K7)	Switch on ignition. Connect multimeter to socket 18 and 11 of test box V.A.G. 1598 Pull parking brake. Release parking brake.	Approximately 12 V Approximately 0 V
8	Engine Coolant Level / Temperature Warning Light (K28)	Connect multimeter to sockets 2 and 13 of test box V.A.G. 1598 Switch on ignition. Remove 2-pin connector at coolant expansion reservoir.	Approximately 12 V Approximately 0 V
9	Glow Plug Indicator Light (K29) (Diesel engines only)	Connect multimeter to sockets 11 and 20 of test box V.A.G. 1598. Switch on ignition.	Approximately battery voltage for the duration of pre-glow (Watch door contact operation)