Quote Originally Posted by Xspook View Post
... not sure how to test if they actually work or not...
I am suspecting there is an error in the trailer wiring. Perhaps where the replacement connector was wired into the wiring at the back, or perhaps up front at the tongue. Or even, possibly, in the vehicle wiring.

I suggest doing basic wiring checks on the trailer. Do not assume anything is wired correctly, let’s verify the wiring is actually correct.

Get a digital multimeter.

And some alligator test wires.

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Also buy a spare pigtail connector for the trailer lamp (3-pin connector with short wire leads), so we can test the LED lamps.

Rig up the 12 volt ‘battery’ thing I posted previously.

Report back, and we can walk you through the testing process.