Question 00 Tundra erratic cruise control

[smitty13]

I recently changed the wiring for my tow package. My truck used to have a U-HAUL power converter. My trailer lights never worked. So I checked the harness, and there was no power coming through the power converter. So I cut the power converter out and spliced in a standard (4) wire: green, yellow, brown, and white trailer harness. The power converter started with (6) wires: black, yellow, red, green, brown, and white. And it goes through the power converter and it converts to (4) wires. I didn't hook up the black ground wire but I had to splice the RED (brake) wire and the BROWN (tail light) wires for my trailer lights to fully work. If I have my headlights on, my cruise control will not work. If I have my headlights off, the cruise control works. But the second I turn my headlights on while having my cruise control on, my cruise control disengages. So I'm half pressed to go buy a power converter to replace the fryed one I cut out. Please give me any feed back. Thanks