Intermittent Problem Diagnosis
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1990 Volkswagen Vanagon, 1990 Volkswagen Jetta, 1990 Volkswagen Golf, 1990 Volkswagen GTI, and 1990 Volkswagen Fox. However, it is still accessible from the selected car via links, so may be relevant.
Intermittent fault testing requires duplicating circuit or component failure to identify the problem. If necessary, monitor voltage or resistance values using a DVOM while attempting to reproduce conditions causing intermittent fault.
A status change on DVOM indicates a fault has been located. When monitoring voltage, ensure ignition switch is in ON position or engine is running. Ensure ignition switch is in OFF position or negative battery cable is disconnected when monitoring circuit resistance.