How to Fix the Most Common (But Little Known) Automotive Wiring Problems

As a long time mechanic, I have seen all kinds of wiring issues with vehicles over the years. Many of these problems often go undiagnosed, leading to bigger headaches down the road. In this article, I want to outline some of the most common (but little known) wiring problems that crop up in cars and trucks, along with tips on how to properly fix them.

1. Frayed Wiring

One of the most common wiring issues I see is frayed or damaged wiring. This is often caused by wires rubbing against sharp edges in the engine bay, or getting pinched against body panels or other components. Frayed wiring can lead to short circuits, electrical fires, and other dangerous situations if not repaired.

Here are some tips for fixing frayed wires:

• Carefully inspect wiring harnesses and looms near hot or moving parts of the engine. Look for any signs of rubbing, pinching, or exposed copper wiring.

• If the insulation is cracked or peeled back, wrap the area with electrical tape as a temporary fix. This can prevent further damage.

• For more permanent repairs, I recommend soldering on a new section of wire to replace the damaged section. Heat shrink tubing can then be placed over the repair.

• If wires are severely damaged, the entire wiring harness may need replacement. A mechanic can source and install a new harness.

2. Corroded Connections

Corroded wires and connections are another issue I often come across in my shop. Corrosion occurs when wiring is exposed to moisture, road salt, battery acid, or other chemicals. Some warning signs include dim lights, electrical shorts, and startup issues.

Here are some tips for cleaning corroded wires:

• Remove the battery terminal connections and scrub away green corrosion using a wire brush.

• Soak heavily corroded wires in a solution of baking soda and water. This can dissolve built-up oxidation.

• Use electrical contact cleaner spray to remove stubborn deposits. This helps restore conductivity.

• Seal connections like battery terminals with dielectric grease to prevent future corrosion.

• Swap out wires or connectors that are too corroded to be salvaged. New replacement parts ensure reliable electrical connections.

3. Loose Connections

Loose wire connections are problematic because they can randomly cut power to important systems like ignition, lighting, or charging. Warning signs of loose wires include flickering dash lights, stalling, and dead batteries.

Here are some tips for troubleshooting loose connections:

• Wiggle wiring harnesses while the car is running to test for intermittent power cutouts.

• Remove and inspect connectors for burnt pins, bent terminals, or spread apart terminals.

• Use a pin extraction kit to securely crimp or solder new terminals onto wires.

• For quick fixes, wrap connections in electrical tape to provide tightness. But this should only be temporary.

• Have a mechanic thoroughly inspect the wiring for any brittle, cracked wire coatings that need replacement.

By properly inspecting, cleaning, and securing automotive wiring connections, many electrical gremlins can be banished for good. Pay attention for any of the warning signs outlined above and make repairs as soon as possible. Taking the time to fix wiring issues will save you from much bigger headaches down the road!