Dodge Ram Trailer Wiring Color Code Guide

Towing a trailer comes with a lot of responsibilities, including making sure your trailer lights are hooked up and working properly. Nothing’s worse than getting pulled over or realizing your trailer brake lights or turn signals aren’t functioning when you’re already out on the road.

That’s why having a handy Dodge Ram trailer wiring color code guide can save major headaches and ensure you make safe, road-ready connections.

This complete guide to Dodge Ram trailer wiring gives a detailed pinout breakdown for 4-pin, 5-pin, and 7-pin connectors. I’ll explain exactly what each wire color powers on your trailer so you can troubleshoot any issues and tow with confidence. Read on to learn how to connect trailer lighting on your Dodge Ram pickup.

In this detailed guide you’ll discover:

• Where to find the trailer wiring connector on Dodge Ram models
• The purpose and wire color for every pin in 4, 5, and 7-pin connectors
• How to test your Dodge Ram’s trailer lights
• Troubleshooting tips for common trailer wiring problems
• Frequently asked questions about trailer connectors

And much more! Let’s start unraveling the mystery of your Dodge Ram’s trailer wiring.

A Quick Primer on Dodge Ram Pickups and Towing Capabilities

Dodge Ram pickups have long been a favorite of contractors, landscapers, and DIY homeowners for their power, performance, and versatility. Early Dodge Ram models packed plenty of capability for work and play, though more recent heavy duty versions have turned into true towing powerhouses.

For instance, when properly equipped the 2022 Ram 3500 can tow trailers up to 37,100 lbs thanks to its high torque Cummins diesel and robust chassis. That makes easy work of hauling even the biggest equipment and large fifth wheel RVs.

Clearly Dodge engineers had trailering in mind when designing these full-size trucks. But all of that towing brawn won’t get you far if your trailer lights and electric hookups aren’t in working order.

Why Proper Trailer Wiring Matters

Behind every capable tow vehicle is an intricate wiring system that powers all of your trailer lights and electric components. Connecting that system properly to your Dodge Ram is the only way to make sure signals like brake lights and turn indicators function reliably.

Trailer wiring issues can do more than just ruin your camping trip or work day. Improper electrical connections can put you and other drivers in danger if your trailer lights malfunction on the road.

Let’s Break Down Those Trailer Connector Pins

The key to flawless trailer lighting is having the correct purpose for each pin that plugs into your Dodge Ram. To hook things up right, you’ll need to decode the wire colors in your truck’s connectors.

This guide will demystify your trailer wiring by covering the color coded pins for standard 4-pin, 5-pin, and 7-pin connectors. Read on to get a wiring diagram with color codes for any trailer setup.

Trailer Wiring Connector Types Found on Dodge Rams

Before jumping into the color codes, let’s look at the different trailer wiring connectors equipped on Dodge Ram pickups from the factory. This will give you an idea of what to expect under your truck’s rear bumper.

The most common configurations are:

• 4-pin flat connector: Basic wiring for trailers with only running lights and turn signals. Used for smaller utility trailers.
• 5-pin flat connector: Adds a reverse light circuit for trailers with backup lamps. Common on recreational / camping trailers.
• 7-pin round connector: The standard for larger trailers. Adds electric brake control and 12V power feed. Typically used for travel trailers, horse trailers, larger cargo trailers, and 5th wheel RVs.

The specific connector equipped from the factory depends on factors like your Dodge Ram’s towing package, gross vehicle weight rating, and intended use.

Heavier duty 2500 and 3500 models typically include a 7-pin since they’re designed for larger towing jobs. Light duty 1500 versions often come with a basic 4-pin plug.

But you can always upgrade your Dodge Ram’s towing harness to support additional trailer functions if needed. For example, adding an electric brake controller requires the blue brake pin found only on a 7-pin round connector.

Next let’s go over where to find these connectors mounted on your truck.

Locating Your Dodge Ram’s Trailer Wiring Harness

All trailer wiring connectors are located under the rear bumper on Dodge Ram pickups. Typically you’ll find a rubber flap or cover that gives access when pulled down or to the side.

On heavy duty 3500 and 2500 models, this flap is often found behind the rear driver’s side tire. For light duty 1500 trucks, look for the wiring access in the center behind the rear bumper.

The connector body itself is either snapped into a bracket or mounted directly to the truck frame/body with screws. Just unplug the wiring harness to reveal the terminal pins.

There may be a small amount of variation on exact connector placement between different Dodge Ram body styles and model year generations. For example, the 5th generation Rams (2019+) appear to mount the trailer plug more centrally compared to previous body styles.

If you can’t locate the connector, check your owner’s manual which should indicate where to find the trailer wiring. You can also have a second person activate the brake lights while you feel along the bumper for the wiring harness.

Next let’s get into those all important wire colors and functions.

Trailer Wiring Color Code Guide for 4-Pin Connectors

The basic 4-pin trailer wiring connector is found on many light duty Dodge Ram 1500 pickups intended for lighter duty towing. It contains the minimum wires needed for basic trailer running lamps and turn signals.

Here is what each colored wire controls in a standard 4-way flat trailer connector:

4-Pin Wire Colors and Functions

• Pin 1 – Yellow: Left Turn Signal and Brake Light
• Pin 2 – Green: Right Turn Signal and Brake Light
• Pin 3 – Brown: Taillight / Running Lights
• Pin 4 – White: Ground

As you can see, this simple 4-pin wiring setup allows you to power all of your trailer’s turn signals and brake lamps, plus connect marker and taillights back to your Dodge Ram’s wiring.

The white ground pin ties everything together, giving the trailer lights a return path for completing their electrical circuits.

Make sure to reference this color chart when hooking up your trailer’s wire harness to identify each pin’s purpose in the 4-way flat connector.

Next let’s look at the additional functions gained by stepping up to a 5-pin trailer wiring connector.

5-Pin Trailer Wiring Connector on Dodge Rams

The 5-pin trailer wiring connector is commonly found on many light duty and some heavy duty Dodge Ram pickups from the factory. It adds a pin for powering reverse lights on your trailer.

Here is how the wires are configured in the 5-way flat connectors installed on most Dodge Rams:

5-Pin Wire Colors and Functions

• Pin 1 – Yellow: Left Turn Signal / Brake Light
• Pin 2 – Green: Right Turn Signal / Brake Light
• Pin 3 – Brown: Running Lights / Taillights
• Pin 4 – White: Ground
• Pin 5 – Blue: Reverse Lights

As you can see, pins 1-4 mirror the basic functions found in a 4-way plug. The addition of the blue reverse light wire in pin 5 allows you to power backup lamps on trailers equipped with them.

Having functional reverse lights on your trailer is important for safety when backing up, especially larger trailers that block rear visibility from the tow vehicle.

So use this 5-pin wiring diagram when hooking up trailer lights or troubleshooting electrical issues on your Dodge Ram.

Next let’s look at the largest 7-pin round connector found on heavy duty towing setups.

Full 7-Pin Trailer Wiring on Dodge Ram Heavy Duty Trucks

The 7-pin round trailer wiring connector is standard on most heavy duty Dodge Ram 2500 and 3500 trucks from the factory. It contains wires for powering additional functions like electric trailer brakes and 12V power supply.

Here is how the wire colors correspond to each pin in a 7-way round connector:

7-Pin Wire Colors and Functions

• Pin 1 – Yellow: Left Turn Signal
• Pin 2 – Green: Right Turn Signal
• Pin 3 – Blue: Electric Brakes
• Pin 4 – White: Ground
• Pin 5 – Brown: Running Lights / Taillights
• Pin 6 – Pink: Reverse Lights
• Pin 7 – Black: 12V Power Supply

The thick blue electric brake wire found only in the 7-pin connector allows you to activate electric brakes on your trailer by tapping into your Dodge Ram’s brake controller.

And the black 12V power wire makes it easy to charge your trailer battery or power accessories like interior lights.

If your Dodge heavy duty truck didn’t come with a 7-way round connector from the factory, you can often upgrade by replacing the wiring harness. Installation is straightforward with some basic tools and wiring knowledge.

Now let’s go over an easy way to test all of your trailer lights are hooked up correctly using these wiring color codes.

Testing Dodge Ram Trailer Light Connections

Verifying all of your trailer lights function properly before hitting the road is a must. Nothing’s worse than getting miles down the highway before realizing your turn signals or brake lights aren’t working.

Here is a quick way to test your trailer light connections using your Dodge Ram’s wiring:

What You’ll Need:

• Helper to activate truck lights
• Trailer wiring harness plugged in

Steps to Test:

1. Have your helper stand at the rear of the trailer and plug in the wiring harness.
2. Sit in the driver’s seat and turn on your emergency flashers. Your helper should see the left and right turn signals flash on the trailer.
3. Turn on the headlights. The trailer running lights and taillights should illuminate.
4. Press the brake pedal. The trailer brake lights should activate.
5. Shift into reverse. Any backup lights on the trailer should turn on.
6. Turn signals and stop lights on the truck should make the trailer’s corresponding lights activate when wired correctly.

If any trailer lights fail to work during testing, recheck the wiring harness color connections against the pinout diagrams above. Make sure there is a good ground and lights are not burnt out.

Refer to the troubleshooting tips next if you encounter any issues getting your trailer lights working.

Finding the Right Dodge Ram Trailer Wiring Diagram

In some cases, you may need to diagnose or repair your Dodge Ram’s exact trailer wiring harness itself.

The best way to get a detailed wiring diagram is to contact your Dodge dealer with your VIN. They can provide the correct harness schematics for your make, model, and year directly from Dodge.

You can also buy a trailer wiring harness repair manual for your specific Ram. Aftermarket brands like Tow Ready offer diagrams and diagnostic info for properly troubleshooting and fixing your wiring harness.

Professional trailer repair shops also have access to wiring diagrams from DrewTech that can assist in pinpointing any trailer wiring faults.

While the basic color codes above cover most situations, having the detailed wiring diagram for your vehicle is useful if you plan to undertake any harness repairs or modifications.

Next let’s go over some troubleshooting tips for the most common Dodge Ram trailer wiring issues.

Troubleshooting Trailer Wiring Problems on Dodge Ram

Despite the best efforts to keep electrical connections clean and snug, trailer wiring issues still pop up from time to time.

Here are some of the most common trailer wiring faults and ways to diagnose them:

No lights working at all:

• Bad ground connection. Check that white ground wire has clean contact to bare metal.
• Fuse blown. Check all fuses related to trailer wiring and replace any burnt out.
• Wiring short. Inspect for any melted/damaged wires shorting out.

Some lights not working:

• Check light bulbs and replace any burnt out bulbs.
• Use a circuit tester to check for power at each pin. If no power on a pin, trace wiring harness back to find disconnect.
• Clean any dirty or oxidized pins not making good contact.

Intermittent lights flickering/cutting out:

• Exposed wiring damaged by road debris or salt causing a short. Inspect harness and cover/repair.
• Bad ground connection causing voltage drop. Wire brush ground pin and bolt to chassis.
• Possible short circuit in trailer wiring. Isolate and test.

Lights dim:

• Heavy power draw from trailer is overloading circuit. May need to upgrade to thicker gauge wiring.
• Alternator not keeping up with demand. Have it tested.
• Poor pin fit causing high resistance. Re-crimp pins or replace connector.

Brake lights stay on:

• Short to ground in the brake light circuit. Test wires and repair.
• Brake controller issue. Calibrate and check brake controller settings.

Start with the basics like blown fuses, bad grounds, and loose connectors when troubleshooting. Check all wiring for breaks, frays, corrosion, or damage.

Use a test light or multimeter to isolate the problem area. Reseating all harness pins can help improve faulty connections too.

If needed, replace corroded or severely damaged harness plugs and wires. And don’t hesitate to bring your Dodge Ram to a trailer wiring specialist for diagnosis and repairs.

Next let’s go over some common questions about trailer connectors.

Frequently Asked Questions About Trailer Wiring

Here are answers to some of the most common questions about wiring trailer lights on the Dodge Ram:

What Gauge Wire Should I Use for Trailer Lights?

For most light duty trailers, 16 or 14 gauge wire is sufficient for basic running lights, turn signals, and brake lights. Heavier duty fifth wheel campers or enclosed car trailers may require a thicker 12 gauge wire for higher current draw.

When in doubt, go thicker – upgrading to 12 or even 10 gauge trailer wire gives you more capacity and reduces voltage drop over long runs.

Where Can I Find the Brake Controller Plug On My Dodge Ram?

The brake controller port for tapping into your tow vehicle’s braking system is typically found under the dashboard on Dodge pickups. Look for a connector tucked up behind the steering column or on the side of the dash. Consult your owner’s manual for the exact location.

Why Don’t My Trailer Reverse Lights Work?

If your trailer reverse or backup lights are not working, start by checking for a blown fuse in the reverse light circuit of your Dodge Ram’s wiring harness.

Also inspect the trailer wiring harness plug for any corrosion on the reverse light pin, as this can cause intermittent contact.

Make sure backup lights are functioning on the truck itself, and wiring from the reverse switch to lights is intact. The reverse signal wire may not be energizing if there’s damage in this circuit.

Let’s Review Those Trailer Wiring Color Codes

Hopefully this guide has cleared up the trailer wiring color codes for the major connector types found on Dodge Ram pickups.

Here’s a quick recap of the basic functions for each wire color:

4-Pin Flat Connector:

• Yellow: Left Turn/Brake
• Green: Right Turn/Brake
• Brown: Tail Lights
• White: Ground

5-Pin Flat Connector:

• Yellow: Left Turn/Brake
• Green: Right Turn/Brake
• Brown: Tail Lights
• Blue: Reverse Lights
• White: Ground

7-Pin Round Connector:

• Yellow: Left Turn Signal
• Green: Right Turn Signal
• Blue: Electric Brakes
• Brown: Tail Lights
• Pink: Reverse Lights
• Black: 12V Power
• White: Ground

Use these diagrams to properly match up each wire color when hooking up trailer lighting. And don’t forget to test all lights before towing.

Proper trailer wiring takes more care and attention than some realize. But good connections ensure safe travels and protect your equipment. Hopefully this guide has decoded the trailer wiring color codes for your Dodge Ram.

Now you can confidently and correctly wire up trailer lighting for smooth, bright, and reliable performance on the road.

Key Takeaways:

• Use included wiring diagrams to identify each wire color’s function when connecting trailer lights.
• Inspect pins for corrosion and check grounds for clean metal contact.
• Test all trailer lights, including turn signals and brake lamps, before towing.
• Check fuses, wiring, and light bulbs when troubleshooting issues.
• Have dealer provide vehicle-specific wiring schematics for repairs.

Specifications Table:

Connector	# Pins	Functions
4-Pin	4	Left/Right Turn/Brake, Tail lights, Ground
5-Pin	5	Left/Right Turn/Brake, Tail lights, Reverse