Troubleshooting LED Clearance Lights on Boat Trailer

Updated 02/27/2017 | Published 02/24/2017

Products Featured in This Question

LED Trailer Clearance and Side Marker Light w/ Flange - Submersible - 5 Diodes - Round - Amber Lens

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$14.23

Dielectric Grease for Electrical Connectors, 2 oz.

(1481)

$10.94

Right Angle 2-Wire Pigtail for Optronics Trailer Lights - 2-Prong PL-10 Plug - 6" Lead

(694)

$4.44

Right Angle 3-Wire Pigtail for Optronics Trailer Lights - 3-Prong PL-3 Plug - 10" Lead

(647)

$8.00

Question:

I have a LED side light on my trailer thats not working. All the other lights are working including the side light on the other side. Given it is a boat trailer im thinking the wiring is broken somewhere as i have checked all the connections. I know the light itself works as I have tested it on the other side they are interchangeable. Im going to run a lead directly to the plug into the car. I need to be able to test this prior to running a new lead to the plug. Question - when i connect the light directly to a 12v battery it doesnt illuminate. There is a push in plug for the connection that im not using and im wondering if that is necessary to wire to and not directly into the lamp itself? Do you think that would be the issue or should the lamp illuminate when directly wired to a 12v battery?

asked by: The P

Expert Reply:

Any trailer light, whether standard incandescent or high-efficiency LED, should light up when it is connected directly to the terminals of a charged 12V battery. Direct connection avoids all other potential causes for problems, such as broken wiring, a weak ground or corrosion, and tells you whether the light functions independent of any other concerns with the trailer's wiring. But since your light works when installed on the other side of the trailer, but not when directly connected to the battery, this suggests that your problem may be related to you not using the wiring connector.

Lights such as # MCL52AB use a 2-prong plug # A46PB for connection. There is also a 3-prong plug # A47PB for lights with that connector type.

Once you have your lights all functioning you might want to use dielectric grease # 11755 on those plug connections to help prevent entry of moisture and dirt.

expert reply by: Adam R