Be careful connecting and electric over hydraulic system to your truck. Check the trail system for compatibility with your truck. You can damage the electric over hydraulic controller in the trailer. Truck companies interfaces to those controllers are NOT equal
My ezloader came with a hydrostar controller and I used it with a 2006 3500 ram. All appeared to be working fine. Some day suddenly the controller was continuously applying brakes. I had a third party brake controller in the dodge that was not compatible with the trailer. Replaced the hydrostar and the break controller and all was working again without issues. Hydrastar makes an additional control box for trucks that are not natively supported. They have a table of supported controllers and trucks somewhere on their website.
Now, I don't know if the truck caused the issue or not. When I opened the hydra star I found moisture in the controller board which could have contributed to the failure. It was raining before. But the trailer was toted for a lengthy period outside and should have failed before. So perhaps the seal was just failing.
Lesson to be learned is to inform oneself about the proper connection between trailer and truck. There is a lot of weight on the trailer. And a ranger tug is just too precious to expose to such risk.
Some trucks allow to adjust for the proper trailer controller. After some other mishap with a broken transfer case I replaced the 06 truck with a 2013 2500 ram with 6.7 Cummins, because of the better mileage, more power and mostly because of the integrated jake brake.
Just checked the hydrastar website and your gmc is not compatible without the adapter module see here
https://www.etrailer.com/Accessories-an ... A-CAM.html