Quick question for you guys. Hopefully, someone can help. I have the factory tow package on the 3.7 Grand Cherokee. It has the 4 pin wiring harness. I just recently bought a boat that has a 5 pin wiring harness. The extra pin is for the reverse lights so that the hydraulic brakes on the boat trailer do not engage when backing up. My questions is, is there an easy way to convert to a 7 pin harness using all the existing wiring or do I need to run a whole new wiring harness from the front?