Troubleshooting Trailer Lights Only Working With Trailer Safety Chains Are Connected To Tow Vehicle

Question:

Trailer connection not working with safety chains off. Put them on it works.five wire to boat. 2019 Explorer Platnum. 4 wire to other trailer works ok, bad ground on my 5 wire to boat or something in vehicle. A safety feature.

asked by: Jim R

Expert Reply:

It only makes sense the ground connection is bad on your boat trailer. Since your 2019 Ford Explorer trailer connector works fine on your other trailer it must be on the trailer. I recommend tracing the ground wire from the trailer connector looking for any damage to the ground wire to the connection point on your frame. If your wire is good you will want to loosen the ground connection and clean the surfaces to ensure they are making good contact.

In the event the ground connection is good but you still do not have the lights working the damage could have occurred to the internal wire. A Test Light # PTW2993 can be used as a jumper to the vehicle ground to check along the trailer wiring to determine if you have an internal break in the wiring.

expert reply by: Bud M