Pop up camper lights won’t light up

[MidTNJeep]

So my brake lights/running lights were working until this last weekend. I have a 4 pin harness on the Jeep that connects to a 4/7 pin adapter and then connects to my trailer. I have a little 4 pin tester that shows a good signal coming from the Jeep connector, brake lights, turn signals, running lights all work. And if I take the male end of the adapter and touch it to the positive terminal on my trailer battery, all the lights light up. But for whatever reason when I connect the adapter to the Jeep, the signal doesn’t get through. Not running lights, turn lights, or signals. Any thoughts?

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[MidTNJeep]

Well after trial and error I’ve answered my own question, I’ll leave it here in case anyone runs into this issue. I had the ground wire of the adapter connected to the frame of the trailer, when in fact it needed to be grounded to the frame of the Jeep. Lights are working now!