My 2000 v8 tundra has the factory hitch with a 4 flat connector for the trailer. My boat trailer is a flat 5 pin. I bought the $20 adapter and crimped the 5th wire for the trailer brake release into the left rear reverse wire on the power side before the bulb. when I turn on the lights thats all I get at the trailer. No blinkers or brake lights. I tested the four pin to find no voltage at 3 of 4 pins. Behind the lr taillght there is a module of some sort. Does this black box house relays for the other lights? Can I bypass the whole thing and splice right up to the 4 pin connector? Any thoughts would be greatly appreciated. Thanks