When probing a connector it is possible to enlarge the contact spring opening. Refer to figure. If this occurs it may create an intermittent signal in the circuit. When probing a connector, use care not to enlarge the opening. If the probe of the Digital Multimeter (DMM) you are using will not fit into the connector cavity, you can back probe the connector with a "T" pin to create an extension. Most DMM's have accessory alligator clips that slide over the probe to allow clipping the "T" pin for a better contact. Refer to figure. If you have any difficulty probing a terminal, inspect the terminal to ensure you have not accidentally opened the contact spring or pulled a wire loose.

Behind The Instrument Panel
Improperly routed or improperly clamped harness can become pinched during accessory installation. Vehicle vibration can aggravate a harness that is routed along a bracket or near a screw behind or below the dash.

Engine Compartment
There are several reasons a vehicle or engine vibration could cause an electrical complaint. Some of the things to check for are:

1. Connectors which are inaccessible for diagnosis probing.
2. Connectors which may not fully be seated.
3. Wiring harnesses that are not long enough and are being stressed during engine vibrations or rocking.
4. Wires lying across brackets or moving components.
5. Loose dirty or corroded ground wires.
6. Wires routed too close to hot components.

To inspect components under hood, start by verifying the integrity of ground connections. Once you have assured the system is properly grounded check for loose connections by gently shaking the wiring or component as previously explained. Using the wiring diagrams in the service manual, inspect the wiring for continuity.

Under Seating Area's
If a harness is not clamped properly or has too much slack, vehicle vibration could cause the wiring to become pinched by seat components such as slide guides. If the wiring runs under seating areas inspect wiring routing for possible damage or pinching.