How to Test Trailer Wiring to Find Short Between Two Circuits
Question:
RV brakes run fine during the day but when I switch on my headlights in my truck and all the trailer lights come on so do the brake lights. I tried switching the wires around at the brake lights that was not my problem. Also it seems when the blinker is on during the day all the lights blink. Can you please Help me
asked by: Jordan W
Expert Reply:
First we need to find out if the problem is your tow vehicle wiring or your trailer wiring. To do this use a circuit tester like part # PTW2993 to test all of the pins on your 7-way for the correct function compared to the diagram I attached.
Next use a jumper wire from a 12 volt battery post to apply voltage to all of the pins of your trailer's 7-way to verify all of the circuits are working like they should. If you see more than one circuit apply when this happens there is a short between those two circuits and you'd have to trace the wiring to find where the short is and fix as needed.
Product Page this Question was Asked From
Featured Help Information
Miscellaneous Media
Continue Researching
- Shop: Trailer Wiring
- Video: Review of the Ford Replacement OEM Tow Package Wiring Harness, 7-Way (Super Duty)
- Shop: Vehicle Seat Covers
- Shop: Covercraft Carhartt SeatSaver Custom Seat Covers - Second Row - Gravel
- Shop: Ford Replacement OEM Tow Package Wiring Harness, 7-Way (Super Duty)
- Search Results: trailer door latch
- Search Results: trailer door holders
- Shop: Buyers Products Hook and Keeper for Enclosed Trailer Door - Zinc Plated
- Shop: T-Style Hook and Keeper Door Holder for RV or Enclosed Trailer - 6" Hook - Stainless Steel
- Shop: Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 7-Way and 4-Pole Flat Connectors
- Shop: etrailer RV Bumper 2" Trailer Hitch Receiver
- Q&A: Troubleshooting Blown Vehicle Fuses Every Time Trailer is Connected
- Shop: 7-Way Molded Trailer Wire Connector, 4' Long
- Q&A: Recommended Sewer Hose Storage For Hose That Wont Fit In Trailer Bumper
- Article: Trailer Wiring Diagrams
- Article: Most Popular Wheel Bearings
- Search Results: pal nut
- Q&A: Troubleshooting Trailer Turn Signal Fuse that Blows When Replaced
- Video: Ultimate Overview of the Bow Roller Assembly w/ Bells for 4" Wide Bracket
- Q&A: What Causes My Trailer Lights To Short Out
- Search Results: electric trailer jacks
- Q&A: Should Keel Rollers Touch the Bottom of the Boat
- Q&A: Boat Keel Is Cutting Keel Roller When Launching Boat
- Article: Troubleshooting 4 and 5-Way Wiring Installations
- Video: Finding the Right Trailer Wiring Harness
- Search Results: trailer hitch
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Shop: Trailer Hitch
- Search Results: trailer brake controller
on Wiring
