How to Keep RAM Tow Mirror Lights On Permanently

To keep RAM tow mirror lights on continuously, bypass the factory wiring by tapping into a constant 12V power source or using a relay. Alternatively, adjust the vehicle's lighting settings or install an aftermarket switch. Solutions range from simple wiring tweaks to advanced modifications for permanent illumination.

Why Tow Mirror Lights Turn Off Automatically

  • Factory design: Most tow mirrors sync with turn signals or brake lights.
  • Power-saving mode: Lights may deactivate after a set time to prevent battery drain.
  • Wiring limitations: Default circuits tie lights to ignition or specific triggers (e.g., door locks).

Methods to Keep Tow Mirror Lights On

1. Tap Into a Constant 12V Power Source

  1. Locate the mirror's wiring harness (usually behind the door panel).
  2. Identify the positive (+) wire for the lights using a multimeter.
  3. Splice into a fused 12V constant power source (e.g., battery or fuse box).
  4. Ground the negative (-) wire to the vehicle's chassis.
  5. Test lights with the ignition off to confirm continuous power.
⚠️ Warning: Use an inline fuse (5-10A) to prevent electrical fires.

2. Install a Relay for Controlled Power

  • Use a SPST (Single Pole Single Throw) relay to isolate the circuit.
  • Connect the relay's coil to the original light trigger wire.
  • Wire the relay's output to a constant 12V source.
  • Lights will stay on but can still be controlled via the original switch.

3. Adjust Vehicle Lighting Settings

  • Check the multifunction stalk or infotainment menu for "trailer light" or "auxiliary light" settings.
  • Enable "Daytime Running Lights (DRL)" mode if available-may keep tow lights active.
  • Consult the owner's manual for model-specific configurations.

4. Add an Aftermarket Toggle Switch

  1. Mount a waterproof toggle switch on the dashboard.
  2. Run wires from the switch to the mirror lights' positive terminal.
  3. Connect the switch to a fused 12V source for manual control.

5. Modify the Body Control Module (BCM)

  • Advanced users can reprogram the BCM to disable auto-shutoff (requires diagnostic tool).
  • Risk of voiding warranties or triggering error codes.

Comparison of Methods

Method Difficulty Cost Permanence Risk of Electrical Issues
Tap into 12V constant Moderate $5-$20 (wires, fuse) Permanent High (if un-fused)
Install relay Hard $15-$30 (relay, wires) Permanent Low
Adjust vehicle settings Easy $0 Temporary None
Aftermarket switch Moderate $10-$25 (switch, wires) Permanent Medium
BCM reprogramming Very Hard $50-$200 (tool/software) Permanent High

Tools and Materials Needed

  • Essential: Wire strippers, crimping tool, multimeter, electrical tape.
  • Optional: Soldering iron, heat shrink tubing, relay kit, toggle switch.
  • Safety: Fuse holder (5-10A), gloves, circuit tester.

Troubleshooting Common Issues

Lights Flicker or Dim

  • Check for loose connections or corroded wires.
  • Verify the power source can handle the load (use a multimeter).

Lights Stay On but Drain Battery

  • Add a battery disconnect switch or use a relay tied to the ignition.
  • Install a voltage-sensitive relay to cut power at 12.2V.

Lights Don't Turn On After Modification

  • Test continuity in wires with a multimeter.
  • Ensure the ground connection is secure and corrosion-free.