I recently bought a previously owned 2006 Toyota Tundra Regular Cab 4x4 without a tow package. I am attempting to add a tow package so that I can tow my boat. The boat trailer has a standard 7 blade RV connector and has electronic brakes. I have no issue upgrading the alternator. I'm ok adding a supplimental transmission cooler. Someone has already added a class IV hitch reciver. I have already mounted a Hopkins Multi-Tow 7 blade towing connector, model 43385, to the hitch receiver using the 4 wire harness already run to the hitch receiver. My question is: "What do I need to add a brake controller? I'm attempting to use/add the factory wire harness if possible."