I have a 2007 Nissan Frontier. It didn't come with a towing package. I have added a towing package to the truck. I bought the 4 pin kit with the relays and installed that. Now I am wanting a 7pin hook up. Are the relays with the 4 pin kit the same as what I would need to use the 7 pin hook up? I'm just wondering what I need to buy to convert my current setup to a 7pin. Ideally I would like to just buy the 7pin harness but I bet I won't come out that easy. Anyone have any info?