Rear Defogger: Testing and Inspection

Rear window defroster, electrical test

Required measuring and test items
- Multimeter VAG1715 (with current probe)
- Test set VW1594 A

Test requirements
- All fuses OK per wiring diagram

- Switch off ignition.
- Remove A/C control head -E87-.






- Remove connector -F- from control head -E87-.
- Switch on ignition.
- Measure voltage between contacts 1 and 2.
Specified value: approx. battery voltage
- Switch off ignition.
- Connect connector -F- to -E87-.






- Guide wire -A- to connector -E- using VAG1715.

NOTE: All connectors connected to -E87-.

- Function "Current measurement via current tool" on VAG1715.
- Start engine.
- Switch on rear heated glass to -E87- (warning light in the button lights up).

Display on VAG1715 changes from approx. 0 A to smaller 25 A.

After approx. 10 minutes display changes from less than 25 A to approx. 0 A (warning light in the button lights up).


NOTE:
- A lower current can be displayed by radiating the current tool with rear window defroster shut off.
- For outside temperatures over 0 °C - E87- switches off the rear window defroster after about 10 minutes automatically.