Vehicles have different wire harnesses, one being the car door wire harness.
As the name suggests, this wire bundle sends and receives electrical signals from the vehicle’s doors to the relevant control module.
You might have noticed part of it when opening the driver/passenger doors or the trunk in a stretchy insulation material near the hinge.
Let’s look at all you should know about this vehicle wiring system component.
Table of Contents
- What Is a Car Door Wire Harness?
- How Much Does It Cost To Replace a Car Door Wire Harness?
- Advantages of Using Car Door Wiring Harnesses
- Typical Issues in Door Wire Harnesses
- How To Pick The Best Car Door Wiring Harness
- Wrap Up
What Is a Car Door Wire Harness?
As stated earlier, a car door wire harness connects the electric switches mounted on the door to the relevant device or control module. The door also houses car speakers. So, this harness also includes speaker wires.
Its location in the vehicle exposes it to wear-causing elements. So, the cable must resist moisture, dust, temperature variations, etc.
However, the primary cause for their wear and tear is the repeated opening and closing of vehicle doors over time.
These actions degrade the insulation as the vehicle ages, affecting the performance of the switches mounted on the door, such as the following.
- Power window
- Wing mirror folding/unfolding
- Door lock actuators
- Wing mirror adjustment
An electric car door lock
Although they wear naturally over time, car door wire harnesses should be durable enough to last long before requiring replacements.
How Much Does It Cost To Replace a Car Door Wire Harness?
Replacing this wire bundle can cost anywhere from $100 to $500, depending on the vehicle’s make and model. But wire harnesses are not costly. The most significant part of this price is the labor for installation.
Therefore, you can save some money by handling the installation yourself. And we recommend buying genuine replacement parts to ensure they fit in the connections without requiring modifications.
You can split this DIY installation into two parts to streamline the process. The first is door grommet installation. Grommets are the flexible rubber pieces you see when opening the door or trunk.
Door harness connections are the second bit of the installation process.
A grommet stretching between the car door and body to secure the car door wire harness
This connection bit involves routing the wires to the terminals in the door and those inside the vehicle.
Avoid channeling these wires near sections with sharp edges, panel joints, or thin sheet metal brackets that can damage the insulation or cut the wires.
Also, use sufficient clamps and clips to keep the bundle clear from these sections.
Also, install the rubber grommets properly to absorb vibrations, seal the wires, and protect them from sharp edges.
Start by connecting the wire harness to the vehicle terminals, then link them to the door switches. Once complete, test the system to determine if everything works. If it doesn’t, recheck the wiring diagram, then redo the electrical connections.
A rubber cover (grommet) for the wire harness in the trunk door
The last resort should be to hire a professional electrician to rectify the improper installation.
Advantages of Using Car Door Wiring Harnesses
This automotive wiring has the following benefits over using individual wires.
Reduced Installation Time
Combining the cables into a single unit simplifies installation, especially when routing them from source to destination. Additionally, the bundle uses less space and minimizes the risk of making incorrect electrical connections.
Multiple wire harnesses in a vehicle’s door
Wire harnesses create organized electrical connections that are safe to handle and less likely to experience electrical circuit faults like shorting.
Also, the bundle is less flexible than individual wires. This rigid structure is sturdier because it resists bending. Wires can snap if bent several times.
These electrical wires are cheaper than individual cables and have a single outer insulation to safeguard the entire bundle. You won’t have to add extra insulation to the single wires.
This unit of less flexible wires has insulations that safeguard the cables inside from vibrations, abrasion, moisture, and other elements.
Typical Issues in Door Wire Harnesses
The common issues you might encounter when dealing with door wire harnesses include the following.
Difficulty Customizing the Car Door Wire Harness
Once installed, modifying the vehicle’s door wiring harness is challenging because accessing the cables is tricky. You might have to remove the door panel to get to the wires.
A technician disassembling a car door panel to access the wire harnesses
Also, if you customize connections in this bundle, you might leave some wires longer than others. This uneven structure won’t be sturdy because some sections can be less rigid.
Plus, if some wires are loose in the bundle, their electrical joints are more likely to short circuit, burn the fuse, or cause fires in the worst-case scenario.
Repairing Broken Wires in the Harness
In some cases, some wires in the harness might get worn out faster than others, causing electrical component malfunction. For instance, you might have the power windows working, but the door lock actuators fail to secure the car.
In such a case, consider replacing the individual wire in the harness rather than the entire bundle. This repair process might be easy or challenging, depending on the extent of the damage.
A technician repairing wires located in a vehicle’s door
Also, a single wire can interfere with the operations of multiple essential components, making the issue more laborious to diagnose.
So, you might have to look for an expert conversant with these broken wire repairs to fix the issue.
Or you can replace the entire harness to avoid the expensive labor cost.
Additionally, one wire breaking might signal that the others are near their end of life, meaning a complete replacement is usually the best option.
How To Pick The Best Car Door Wiring Harness
Replacing the entire car door wire harness might be better than fixing individual wires. So, consider the following factors when shopping for a new one.
- Always use stranded wires instead of the solid core type. These wires are sturdier and can withstand vibrations for longer without breaking. Generally, vehicle harnesses contain stranded wires, but it won’t hurt to check. And if you decide to do repairs, always use stranded cables.
- Consider the space and size constraints. The wire bundle should be compact enough to fit inside the grommet and through the door holes. But it should also be wide enough to transmit the required electric signals.
A mechanic fixing an electronic door lock
- Pick a weatherproof wire harness for maximum durability. The weatherproof seal should protect the wires from water and engine fluids, such as oil.
- Ensure the terminations on the harness match the electrical connections in the vehicle. Incorrect terminals might require modifications (new terminal crimping) or returns, and all result in a loss of time.
- Check the electrical capacity or power rating of the wires in the bundle. They should at least match the rating of the harness you are replacing. Thicker wires are better, but these might cost you more or increase the vehicle’s weight, albeit with a tiny margin.
The car door wire harness is a critical component of the vehicle wiring system, and it has its advantages over using individual cables.
Like other wire bundles, this one wears naturally over time and might need replacements to keep door switches fully functional.
We recommend changing the entire harness instead or repairing single wires if the damage is extensive and challenging to troubleshoot. Otherwise, you can cut the damaged section and crimp a new piece.
That’s it for this article. Contact us if you need further guidance. Have a good one!