Identifying Intermittent Conditions

Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movement of a component. Refer to the following for a list to help isolate an intermittent condition:

• Water intrusion in connectors, terminals, or components
• Poor connector mating
• Terminal contact
• High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
• Harness' that are routed too tight, or chaffed circuits
• High or low ambient temperatures
• High or low engine coolant temperatures
• High underhood temperatures
• Heat build up in components or circuits due to circuit resistance, poor terminal contact, or high electrical load
• High or low system voltage
• High vehicle load conditions
• Rough road surface
• Electro-magnetic interference (EMI)/circuit interference from Relays , solenoids or other electrical surge
• Incorrect installation of non-factory, aftermarket, or after factory add on accessories

If an intermittent fault is detected, refer to Testing for Intermittent Conditions and Poor Connections for specific strategies in diagnosing intermittent conditions.