1985 Chevy Truck Wiring Harness Diagram

If you’re looking for a wiring harness diagram for your 1985 Chevy truck, you’ve come to the right place. Whether you’re restoring an old truck or just need to replace a faulty wiring harness, having a diagram can be extremely helpful.

What is a wiring harness?

A wiring harness is a collection of wires that are bundled together to connect various electrical components in your vehicle. This includes everything from the headlights to the radio to the engine management system.

The wiring harness can be thought of as the nervous system of your vehicle. It allows all of the various electrical components to communicate with each other and ensures that everything is working properly.

Why do you need a wiring harness diagram?

If you’re working on your vehicle’s electrical system, having a wiring harness diagram is essential. It allows you to see where all of the wires go, which can be especially helpful if you’re trying to troubleshoot an electrical problem.

Without a diagram, it can be difficult to know which wire goes where, which can lead to confusion, frustration, and even damage to your vehicle.

Where can I find a wiring harness diagram for my 1985 Chevy truck?

There are a few different places you can look for a wiring harness diagram for your 1985 Chevy truck. Here are some options:

1. Online forums and websites

There are many online forums and websites dedicated to vintage Chevy trucks. These can be great resources for finding wiring harness diagrams, as other truck enthusiasts may have already done the research and shared their findings online.

Just be sure to double-check any information you find online to make sure it’s accurate and applicable to your specific truck.

2. Repair manuals

Another option is to consult a repair manual for your 1985 Chevy truck. Many repair manuals include wiring diagrams, which can be very helpful when working on your vehicle.

You can find repair manuals at your local auto parts store or online. Just make sure to get one that’s specific to your make and model of truck.

3. Chevy dealership

If all else fails, you can always visit your local Chevy dealership and ask for a wiring harness diagram. They may have one on file or be able to order one for you.

Understanding the Wiring Harness Diagram

Now that you have a wiring harness diagram for your 1985 Chevy truck, it’s important to understand how to read and interpret it. Here are some key things to keep in mind:

1. Color coding

One of the most helpful things about a wiring harness diagram is the color coding. Different wires are typically color-coded to help you easily identify which wire is which.

The color coding can vary depending on the make and model of your vehicle, so be sure to consult the key on your specific diagram.

2. Symbols

Wiring harness diagrams often use symbols to represent different components or parts of the electrical system. Some of the most common symbols include:

Battery +
Switch +
Lights +

3. Labels

Finally, wiring harness diagrams often include labels for different components or wires. These can be especially helpful when trying to trace a specific wire or troubleshoot a problem.


1. How do I know if my wiring harness is faulty?

There are a few signs that your wiring harness may be faulty, including:

  • Dimming or flickering headlights
  • Electrical components not working properly
  • Burning smells or smoke coming from the dashboard

If you suspect that your wiring harness is faulty, it’s important to have it inspected by a professional as soon as possible.

2. Can I replace my wiring harness myself?

Replacing a wiring harness can be a complex and time-consuming process, so it’s typically best left to a professional mechanic. However, if you have experience working on vehicles and feel confident in your abilities, you may be able to do it yourself with the help of a repair manual and wiring harness diagram.

3. How often should I inspect my wiring harness?

It’s a good idea to have your wiring harness inspected regularly as part of your vehicle’s regular maintenance routine. This can help identify any potential issues before they become major problems.

It’s especially important to have your wiring harness inspected if you notice any signs of electrical problems, such as dimming headlights or malfunctioning components.


A wiring harness diagram can be an invaluable resource when working on your 1985 Chevy truck. Whether you’re replacing a faulty harness or just need to troubleshoot an electrical problem, having a diagram can make the process much easier and more efficient.

Remember to consult your specific wiring harness diagram and take your time when working on your vehicle’s electrical system to ensure safety and accuracy.