Trailer Right Tail Light Keeps Blowing on a 2005 Vintage Trailer

Question:

Hi - Im trouble shooting my boat trailer tail lights and Im down to a problem with the right tail light fixture or bulb. Heres what I know - 1 the tow vehicle wiring was tested and is fine, 2 both tail light night running lights work fine, 3 the trailer wiring, including the white ground appear good with solid connections, 4 the left turn light and brake light work fine, 4 the right turn light and brake light do not work. When I replaced the right tail light bulb - the right turn and brake filament blew immediately. In inspecting the original right tail light bulb the turn and brake filament was also blown. Question - should I replace the entire right tail light fixture or try some different bulbs? The fixture number is 440-15 and the bulb number Im using is 1154 LL. The trailer is a 2005 vintage, is in very good condition and has been kept in doors must of the time and throughout the winter

asked by: Donald R

Helpful Expert Reply:

The light blowing not once but twice indicates to me that there is a short circuit that is overloading the right side. First, you will need to isolate the short or this will just keep happening. Start with the vehicle side and trailer side connectors. You will need to make sure that they are clean and corrosion-free. Then make sure each is properly grounded to clean and corrosion free bare metal surfaces.

Check the wiring leading back to the right side. You will be looking for any breaks in the wiring with exposed copper strands that might be touching a bare metal surface. Also you will check the right side ground connection and if there is any dirt or corrosion clean it off.

Doing all of this should locate the short and you should be able to put on a new tail light. Based on the tail light number you have provided the correct replacement should be # 432200.

expert reply by: Michael H