You don’t take the lights in the travel trailer for granted, but they are essential. They determine your safety and the safety of other drivers, which is why there are rules that impose fines when these lights are defective.
However, no one can stop lights from being exposed to the many weathers, atmospheres, and landscapes that cause flaws in them. You don’t want your brake, turn signal, stop lights, or other trailer lights to be inoperative when you enter traffic. How can you prevent this from happening?
Ensuring the proper functioning of trailer lights is paramount for safe towing. Whether you’re a seasoned haulier or a novice, using a multimeter to test your trailer lights is a valuable skill. This versatile tool lets you quickly diagnose and fix any electrical issues, ensuring that your trailer’s lights, including brake lights, turn signals, and taillights, are in working order.
This article explains how to diagnose problems with your trailer lights, including how to quickly identify problems with a multimeter. Let’s start now.
Diagnosing A Problem With Your Trailer Lights
There are two techniques to identify the cause of your trailer light issue. Depending on the final strategy you use, these can be simple or complex. The two techniques comprise
- checking for damaged lights
- bypassing the plugs on the trailer hookup and tow wire system.
Of course, the easier course of action is to look for a burned-out light before digging into the trailer plugs. Simply install new lights and check to see if they work. You go to the following diagnosis step if the new lights don’t function.
To identify whether the issue comes from the trailer connectors or plugs or whether there is only a simple wiring connection issue with the light wires, it is important to bypass the tow wiring. To test whether the lights work, you connect the light wires directly to the tow vehicle wiring after removing the connector that connects the tow and trailer.
If the lights aren’t working, you can infer that there might be a problem with the wires.
On the other hand, if the lights function, the issue can be with your connector or trailer plug, requiring additional testing. You require the following tools to accomplish this.
- Multiplex meter
- A test bulb
Read Also: how to test a motherboard with a multimeter
Why does a Trailer Light not Work?
A faulty ground connection causes many trailer wiring issues. It is often the white wire coming out of the trailer connector. If the ground is bad, lights might only occasionally work or not work at all.
Check the ground connection to the trailer frame even if the wiring to the socket is correct. It should be spotless, free of paint and rust, and securely fastened. Suspect the ground if you use a turn signal but it doesn’t glow as brightly as it should.
How to Test Trailer Lights with a Multimeter
Normally, exposing your trailer to grit, filth, snow, rain, and sun can harm your trailer’s lighting since it encourages the growth of numerous technical flaws. As a result, you should constantly check to make sure your trailer lights are working properly.
Analytical Test
Check that the problem is with the connectors and not something else before grabbing your multimeter. How do you make that happen?
- Since your light bulbs rather than the travel trailer lights may be the cause of the issue, replace them first.
- If it still isn’t working, the wiring may need to be checked.
- Disconnect the cords that link the main vehicle and the trailer.
- To verify this, the lights directly to the trailer.
- You’ll need to use your multimeter if the lights still don’t function.
Ground Connection Test
- Using a multimeter, conduct a ground connection test.
- The multimeter must now be used to check the ground connection.
- Hold the black and red, or negative and positive, multimeter probes in the proper positions.
- The multimeter should be modified to Ohms or resistance for grounding testing.
- Connect the probes to make sure they work.
- Connect the black search to the negative terminal and the red probe to the grounding. About 0.3 ohms should be shown on the multimeter.
Test for trailer plugs
You should test your trailer plug after evaluating the possibility of grounding as the problem. It’s to make sure it’s getting the proper voltage. To avoid confusion, make sure you comprehend your connector and every wire. It could result in an incident or a mistaken action. As a result, some multimeters have standard labels while others have different color codes.
To do your trailer plug test
Connect your multimeter to the black negative wire, setting it to direct current (DC) volts.
The light controlled by that pin can be turned on by connecting the opposing wire to the positive terminal.
The plug being tested is not the problem if the multimeter reads the same number of volts as that plug.
Voltage Test
If you haven’t already found a problem, use this to check the voltage.
To find out which cables connect to a specific light, look at your connection. Four wires, each with a distinct color, plus a white grounding wire are often present.
To measure the voltage, set the multimeter’s voltage setting. Ensure that it is set up to measure both DC and AC. For DC, a straight line is used as a sign.
Connect the red probe to one of the light leads and the black probe to a negative terminal. After that, turn on the lights.
Take notes on what you read. The reading on your multimeter that corresponds to the voltage of the battery you are using should be shown. Therefore, the reading should indicate 12 volts if the battery should be 12 volts.
Connector lighting test
Resistance must be measured to evaluate the lighting connection. To do this, adhere to the directions below:
- A multimeter should be adjusted to measure resistance (ohms).
- Multimeter leads should be connected to the instrument.
- Connect the black search to the ground connector and the red probe to each point pin.
- Take notes on what you read. Your wiring system is in good operating order if the value is 3 ohms.
For wirings, such as those supplying the turning and baking lights, many controls are necessary. Remember that these cables have a series of connections as well. The reading value from your multimeter can have low resistance.
You should separate these wires, examine each one separately, and then remove the bulbs to prevent issues. Release the brake lights so that the multimeter only reads the right lights to analyze the correct signal. While capturing the displayed data, repeat this procedure with the additional lights.
Conclusion
In conclusion, testing trailer lights with a multimeter is a straightforward and essential process for ensuring the safety and functionality of your trailer lighting system. By following the steps outlined in this guide, you can diagnose and fix any electrical issues before hitting the road, reducing the risk of accidents and legal troubles.
Remember, a multimeter is a versatile tool that can help you check various aspects of your trailer lights, such as voltage, continuity, and bulb functionality. Regular maintenance and testing of your trailer lights should be a part of your routine to ensure a smooth and safe towing experience.
FAQs
Are there any safety precautions I should take when testing trailer lights with a multimeter?
Always disconnect the trailer from the towing vehicle and turn off the trailer’s power source before testing. Handle electrical connections with care to prevent electrical shocks or short circuits.
What should I do if I find an issue while testing trailer lights?
If you discover problems, such as no voltage or continuity, check the wiring, connections, and bulbs for damage or corrosion. Repair or replace any faulty components to ensure proper function.