Three Flashing Lights on Hopkins 7-Way RV Style Trailer Connector HM48503

Updated 06/13/2025 | Published 03/25/2023

Question:

Why do I have three flashing lights on my plug what can be yhe problam

asked by: Randall

Expert Reply:

In regards to the Hopkins 7-Way RV Style Trailer Connector part # HM48503, the left turn "LT" and right turn "RT" signals are the only ones that should be flashing while activated. If you have other circuits flashing that means there is a short between circuits. I first recommend opening up the connector and seeing if you find any corrosion. If not, the issue could be on the vehicle so take a circuit tester and test the pins inside the trailer connector. If not, the issue is on the trailer and you'll need to start tracing wires.

I have attached a few photos below that will help with taking the connector apart.

expert reply by: Conner L

Three Flashing Lights on Hopkins 7-Way RV Style Trailer Connector HM48503
(click to enlarge)

Pete C.

6/13/2025

When I turn on my left turn signal the center LED light comes on. Then researching to find out what that center light refers to, but not a lot of luck. Hopefully you can help. Thank you.

Jesse M.

6/13/2025

@PeteC Typically the center pin on a 7-way is wired to auxiliary power or reverse lights. Here are the wire functions for the # HM48503 adapter: Green: right turn signal (RT) Yellow: left turn signal (LT) White: ground Brown: tail light and side marker lights (TM) Blue: electric brake (EB) Red: auxiliary (AX) Purple: backup/reverse lights (BU)