Display Field No. 4
WARNING: This page is about a different car, the 2003 Volkswagen EuroVan and 2002 Volkswagen EuroVan. However, it is still accessible from the selected car via links, so may be relevant.
Voltage supply to terminal No. 1 (Black wire) of Climatronic Control Module (CCM) 28-pin harness connector "A" should display battery voltage. Check for open or short to ground in Black wire.