How to Replace the Wiring Harness in a 1987 Yugo

Introduction

Replacing the wiring harness in a 1987 Yugo can be a daunting task, but with some preparation and patience, it is very doable for a mechanically inclined owner. In this guide, I will walk through the complete process of replacing the wiring harness in a 1987 Yugo from start to finish.

Reasons for Replacing the Wiring Harness

There are a few common reasons why you may need to replace the wiring harness in your 1987 Yugo:

• Electrical issues: If you are experiencing a lot of electrical gremlins, such as lights flickering, instruments malfunctioning, or circuits randomly shutting off, chances are there are worn out or damaged wires in the harness. Replacing it can resolve these problems.

• Corrosion: Over time, the wires in the harness can corrode from moisture, salt, and other contaminants. This can cause electrical shorts and other problems.

• Modifications: If you are adding electrical accessories like a new stereo, lights, or other components, you may need to install a new wiring harness to integrate everything.

• General maintenance: The wiring harness is like any other component and wears out over time and miles. Replacing it as preventative maintenance is a good idea.

Preparing for the Job

Replacing the wiring harness is not a small job, so preparation is key. Here are some things you should do before getting started:

• Get a wiring diagram: This is essential for properly installing the new harness. Make sure to get a diagram specific to your 1987 Yugo.

• Buy the new harness: Purchase a complete harness made specifically for your Yugo's make, model, and year. Aftermarket ones are available online and from auto parts stores.

• Rent or buy special tools: You may need items like wire crimpers, cable cutters, and wire strippers. A test light and multimeter will also help troubleshoot.

• Clean the engine bay: Remove clutter, dirt, and grease so you have clean access to all the wiring and connections.

• Have replacements on hand: Get new wire ties, electrical tape, connectors, etc. to properly secure and insulate all the new wiring.

Removing the Old Harness

With the prep work complete, it's time to remove the old wiring harness:

1. Disconnect the Battery

Always disconnect the negative battery terminal before working on any electrical components. This prevents accidental short circuits while the harness is being handled.

2. Remove Accessible Components

Take out anything mounted over or surrounding the harness like the air filter housing. This creates the necessary access.

3. Locate and Label all Connectors

Use small tags or tape to identify what each connector plugs into (alternator, distributor, temperature sensor, etc). This will make reconnecting easier.

4. Disconnect the Wires and Remove the Old Harness

One by one, detach the labeled connectors until the entire harness can be removed from the vehicle.

Installing the New Harness

With the old one out of the way, now a new wiring harness can be installed:

1. Position the New Harness in Place

Lay out the new harness in the same position as the old one securing it loosely with tape as needed.

2. Reconnect the Main Wires

Attach the main power feeds to the battery, alternator, fuse box, etc based on the wiring diagram.

3. Route the Wires Properly

Make sure wires take the correct path through firewall openings and avoid moving components, heat sources and sharp edges.

4. Reconnect All Wires Per Diagram

Following the wiring diagram, reconnect all connectors to components using the labels made during removal.

5. Secure the Harness

Use zip ties, electrical tape and retaining clips to secure the new harness safely in position.

6. Replace Access Components

Reinstall any components, covers and hardware that were removed for access.

7. Reconnect Battery and Test

Reconnect battery, then turn the key to test all electrical systems. Check for proper operation.

Finishing Touches

With the major work done, there are just a few small tasks left to button it up:

• Inspect for loose wires or improper routing and correct as needed.
• Verify connectors are fully seated and tightened.
• Clean any grease or dirt that got on the new harness and components.
• Start the engine and test headlights, wipers, radio and everything electrical.
• Take it for a short test drive to confirm normal operation.

And that completes the full wiring harness replacement on your 1987 Yugo. While involved, taking your time and following the wiring diagrams closely makes the job very manageable. You now have clean, reliable wiring for years to come.