RSA964993

I’m hoping that somebody has a quick solution to this as I’m about to embark on a trip pulling my trailer. I have a 20 foot enclosed featherlite trailer that I pull with a 2015 Range Rover. This set up although not ideal, has worked fine for years. Recently I noticed the top left rear trailer light worked intermittently unless I hit it and it would work again. I replaced the light by replacing it with a new unit that basically plugged into the existing socket that was coming out of the trailer. It turns out the light I replaced was full of water.

When I went to test the new light neither lights on the left side (upper and lower) worked when testing the brakes or the left turn signal. When I turned on the headlights they both lit right up but when checking turn signal and brakes they didn’t work. The lights on the right side of the trailer don’t have any issues.

I’ve learned that within the 7 socket plug that goes into the truck from the trailer that there is a specific connection that is for the left turn signal and brake light on the trailer. I’m in a pinch for time so does it make sense to assume that the plug from the trailer might be bad and just replace that?

Everything on the Range Rover works fine and I’m not getting any notices or chimes that something is amiss within the truck.

Any ideas would be appreciated. Thanks.

Mussl Kar

Somewhere somebody makes a 7 pin test plug in unit. Sim to an electricians outlet tester. I would check if Rover has same issue, then check wheel wells on trailer for broken wires, then check the rear door wind up area to see if anything is amiss there. Another friend had the cable pull up a warning thingy and as it wrapped it around the drum it ripped out some of the wires.
Does trailer have a fuse panel? Mine does not so must rely on tow fuse panel?

RSA964993

Thanks for the response. I’m going the route of the 7 pin test unit as a start. There is no fuse box for the trailer. If it’s not the 7 pin I’m going to trace all of the wiring back because the trailer is always outdoors and certainly when moving bounces around a bit. I’m hoping it’s a simple thing. I’ll check back when I figure it out.

Matt Romanowski

The testers are like this
I consider them a requirement in the tow vehicle because they help you start diagnosing issues so fast. Did you replace the bulb or the entire housing? Same part or LED? I can't remember the exact numbers, but there are two bulbs that look the same but operate differently as far as power going through them which could cause a problem like you are having. LED bulbs mess with the resistance that some cars look for and can cause a problem (if you didn't have one before and replaced a regular bulb with a LED).

RSA964993

Matt- Thanks. I replaced the entire light housing and I noticed the light was different than the original one. I’m guessing that the original light was 11 years old and this was what the best match was. I was able to stop at GGT on my way to VIR and they determined that somewhere in the cord behind the 7 pin of the trailer and the rear trailer lights there was some type of short. I guess it’s unusual because it’s a fixed cable that rarely fails. They didn’t have one in stock and when they reassembled everything...the lights worked. Something must be loose in that cord and I’ll get it replaced when it comes in.