Do you want to feel safe when you have an RV emergency on the road?
Do you want to check all your lights without going back and forth to the tow vehicle?
Do you need to disconnect your tow vehicle, but you want the trailer to be visible to traffic?
You can choose to just turn the trailer lights on or have the lights flash as a sign of emergency.
The roadside isn’t the only place where having flashing lights may also be useful. Suppose you’re traveling, RVing or boondocking somewhere and are in need of emergency assistance. Maybe you can call for help on your cell phone but how in the world can you give specific directions to your location (a GPS device can help here also). Those flashing running lights out in the darkness could be the beacon emergency response people need to find you.
How To:
The key is to connect the flasher to your trailer’s umbilical plug as shown in the illustration. The two white arrows shown in the diagram below are pointing to the top two pins of the plug. The pin on the left is #4 and is the battery charging line (Battery +ve), the right pin, #3, supplies power to the license, tail and running lights.
Note: The wire color alone should not be relied on, always test and match the function to the appropriate terminal.
7-way RV Tow Vehicle Connector Wiring Color Code
| # | Color | Gage | Circuit Function | Connector Interior |
| 1 | White | 10 | Common Ground |  |
| 2 | Blue | 12 | Electric Brake | |
| 3 | Green | 14 | Tail/running Lights | |
| 4 | Black | 10 | Battery Charge (+) | |
| 5 | Red | 14 | Left turn/stop | |
| 6 | Brown | 14 | Right turn/stop | |
| 7 | Yellow | 14 | Auxiliary/back up | |
| Note: #7 is the center terminal and currently is most commonly used for backup lights | ||||
7-way RV Travel Trailer Connector Wiring Color Code
| # | Color | Gage | Circuit Function | Connector Interior |
| 1 | White | 10 | Common Ground | |
| 2 | Blue | 12 | Electric Brake | |
| 3 | Green | 14 | Tail/running Lights | |
| 4 | Black | 10 | Battery Charge (+) | |
| 5 | Red | 14 | Left turn/stop | |
| 6 | Brown | 14 | Right turn/stop | |
| 7 | Yellow | 14 | Auxiliary/back up | |
| Note: #7 is the center terminal and currently is most commonly used for backup lights | ||||
7-way RV Connector Wiring
Enhanced RV Emergency Flasher
I didn’t want to try to remember how to make the above RV emergency flasher during an emergency in the dark, so I made the RV emergency flasher. It’s very simple and easy to use as all you have to do is plug in the unit into your trailer’s umbilical plug.
I added a fuse between the #4 (battery source) and the flasher for safety.
Wiring Diagram
You could also wire it so the running lights are on solid and only the brake lights flash.