Understanding Key Aspects of Subaru Electrical Connectors and Diagnosing Issues

Understanding Subaru Electrical Connectors

Subaru vehicles are known for their reliability, safety, and performance. An important but often overlooked component that contributes to these qualities are the various electrical connectors throughout Subaru models.

Types of Subaru Electrical Connectors

There are many different types of electrical connectors used by Subaru depending on the application. Some common ones include:

• Battery terminals - Connect the positive and negative battery cables
• OBD-II connector - Allows scan tools to access the engine computer
• Fuse box connectors - Interfaces with fuse box to distribute power
• Lighting connectors - Connect wiring harnesses for exterior lights
• Sensor connectors - Allow engine and transmission sensors to provide input signals

Location of Main Electrical Connectors

Knowing where key electrical connectors are located on Subaru models allows for easier troubleshooting. Here are some main connector locations:

• Battery - Engine compartment near the front left fender
• OBD-II - Underneath dashboard on driver's side
• Fuse Box - Underhood on firewall or under dashboard
• Lighting Connectors - Behind headlights, taillights, etc.
• Sensor Connectors - Attached to sensors mounted throughout engine and transmission

Electrical Connector Failure Points

While electrical connectors are generally robust components, they can still wear out over time. Identifying potential failure points can help prevent and diagnose issues.

Corrosion

Corrosion buildup is an enemy of electrical connectors. Salt, dirt, moisture, and air pollution can cause corrosion. This corrosion can prevent a clean connection resulting in electrical gremlins and faults. Periodically cleaning connections helps prevent this.

Vibration Damage

The vibration from engine operation along with driving on rough roads can fatigue and damage electrical connector housings and terminals. This can cause intermittent electrical problems that may be hard to reproduce. Inspecting connections for cracks and broken locking tabs can identify this issue.

Heat Damage

Underhood electrical connectors near exhaust components, turbochargers, and other hot spots can become brittle and damaged from prolonged heat exposure. The wiring insulation can also degrade leading to electrical shorts. Relocating or shielding sensitive connections helps avoid heat-related failures.

Diagnosing Subaru Electrical Connector Issues

Diagnosing problems with Subaru electrical connectors takes skill and the right tools. Here is an overview of effective troubleshooting approaches.

Visual Inspection

The first step in diagnosing connector problems is a thorough visual inspection. Check for corrosion, damaged or degraded housings/terminals, burnt or melted areas, etc. Fix any obvious issues before moving to the next steps.

Wiggle Testing

Gently wiggle each connector and wire harness while the vehicle is running. If wiggle testing replicates an electrical fault like warning lights, dimming headlights, or drivability problems, there is likely a loose or intermittent connector.

Voltage Drop Testing

Use a digital multimeter (DMM) to check voltage drops across suspect electrical connectors. Any more than 0.2V drop means there is excessive resistance which can cause electrical component damage or failure over time.

Repairing Damaged Connectors

Damaged Subaru electrical connectors need to be repaired or replaced. Carefully inspect mating terminals and housings. Replace individual terminals if possible. Use dielectric grease when reassembling to prevent future corrosion. Replace badly corroded connectors.

Properly diagnosing and repairing electrical connector problems on Subarus requires quality tools, wiring diagrams, and repair procedures. Consulting a professional Subaru technician can save significant time and effort.

FAQs

What are the most common Subaru electrical connector issues?

The most common Subaru electrical connector failures are due to corrosion, vibration damage causing cracked housings, and heat damage resulting in melted connectors. Poor connections cause intermittent electrical faults.

Where is the OBD-II connector located on Subarus?

The OBD-II connector is located under the dashboard on the driver's side of most Subaru models. This allows scan tools to access the engine computer for diagnostic testing procedures.

Should dielectric grease be used on Subaru electrical connections?

Yes, using dielectric grease on connections can help prevent corrosion caused by dirt, moisture, and other contaminants. It fills small spaces to block out moisture and provides enhanced conductivity.

What is the maximum acceptable volt drop across Subaru connectors?

Voltage drops over 0.2V when measured across Subaru electrical connectors often indicates excessive resistance which can damage components. This threshold helps identify connectors in need of repair.