Troubleshooting Trailer Brakes Locking Up Every Time Connected To 2004 Chevy Silverado with 7-way

Question:

The trailer brakes lock up when I connect to my trailer. I have a 2004 Silverado that I bought used with a 7 point connector. I removed the plug and wanted to check the wiring. Is that the right thing to do? How do I get into the housing where the wires are connected?

asked by: Nic

Expert Reply:

The first thing to do is to check your wiring functions based on location as there is a chance there are wire positions out of order. For this, use a circuit tester like # PTW2993. It is not uncommon for someone to have reversed the 12V power on a 7-way with the brake controller wire on either the vehicle or the trailer if they installed it themselves. If this is switched, the trailer brakes will lock up every time you connect your trailer. I've attached an article and a photo to assist.

Since your connector has a covered housing, you will need to replace it as you will need to cut the wires from a molded housing.

It is also possible that there is a bent pin causing issue in the US Car Connector if you have a factory 7-way. If there is a bent pin, I recommend the Replacement Custom Multi-Tow 7-Way and 4-Way Trailer Connectors # 30955. If you don't have this style connector, then you can splice one in using the 4' Pigtail Wiring Harness for Pollak Replacement 7-Pole RV Socket # PK11998.

If the molded connector is wrong on the trailer side and you want to replace it, I recommend using the 7-Way Molded Trailer Plug with Junction Box # HS381-9000 for an easy fix.