Troubleshooting LED Lights on Trailer Not Lighting Up

Question:

SO as you can see from the subject line, I have a LED trailer with LED lights and a truck with incandescent lights. The trailer lights work with another truck but not with mine. I have a Hopkins connector for a four pin and added a 7 pin for the current Airstream with electric brakes. The Hopkins is not marked as LED compatible. I checked the connector with a test light and it blinks. Unfortunately when I put a meter on it, I can see it is getting current but my meter is not fast enough to tell me how many volts I am getting. By the way, it appears that the brake controller is seeing the trailer because when I step on the brakes, it indicates how much power it is sending to the trailer brakes. I can convert the vehicle lights to LED by adding the bulbs as well as resisters. but do I need to add the Hopkins connector for LEDs? In other words, if you were going to set up a trailer with LED lights and incandescent on the tow vehicle from scratch how would you do it?

asked by: Joe K

Expert Reply:

You could remove your current Hopkins wiring and install the Hopkins # HM48895 that you referenced but I recommend simply installing load resistors like part # DI34ZR instead. These put a higher load on those light circuits which then let your current wiring know to send power.

The reason that your brake controller is registering that your trailer is connected but not your lights is because it is on a completely different circuit. The P3 # 90195 that you have installed sends a small pulse to check and see if a trailer is connected so as soon as you connect your trailer it recognizes it.

expert reply by: Jon G