For 1990-2009 cars

### Intermittent and Poor Connections

Most intermittents are caused by faulty electrical connections or wiring. Occasionally a sticking relay or solenoid can also cause an intermittent failure. Some items to check are:

• | Poor mating of connector halves, or terminals not fully seated in the connector body (backed out).

• | Dirt or corrosion on the terminals.

• | The terminals must be clean and free of any foreign material which could impede proper terminal contact.

• | Damaged connector body.

• | Exposure of terminals to moisture and dirt causing improper terminal orientation with the component or mating connector.

• | Improperly formed or damaged terminals.

• | Check all connector terminals in problem circuits in order to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to Checking Terminal Contact in this section for the specific procedure.

• | Poor terminal to wire connection.

• | Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire to terminal contact area, etc.

• | Wire insulation which is rubbed through.

• | This causes an intermittent short as the bare area touches other wiring or parts of the vehicle.

• | Wiring broken inside the insulation.

• | This condition could cause a continuity check to show a good circuit, but if only one or two strands of a multi-strand type wire are intact, resistance could be far too high.

To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair detailed in Wiring Repairs and Connector Repairs.

#### Checking Terminal Contact

When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to the J 38125-A Terminal Repair Kit or the J 38125-4 Instruction Manual for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. When diagnosing an electrical system that utilizes Metri-Pak

Frequently, a diagnostic chart leads to a step that reads: Check for poor connection. Mating terminals must be inspected to assure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation.

Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit.

Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit.

Follow the procedure below to check terminal contact.

1. Separate the connector halves. Refer to the J 38125-A Terminal Repair Kit or the J 38125-4 instruction manual.
2. Inspect the connector halves for contamination. Contamination will result in a white or green build- up within the connector body or between terminals, causing high terminal resistance, intermittent contact, or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals, and connector body.
3. Using an equivalent male terminal from the J 38125-A Terminal Repair Kit, check the retention force is significantly different between the two female terminals, replace the female terminal in question (refer to the J 38125- A TerminalRepair Kit.

If a visual (physical) check does not reveal the cause of the problem, you may have the vehicle with a DMM connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit.