i can not belive that i wasted 2 weeks of my spare time to find this. Have not seen this for decades and if you have a weird electrical problem, look where no one else thinks to.... 68 Z28 wipers don't stop problem. All parts new or like new and??? The Bulkhead/fusebox connector to the new fusebox and half new and half original wires. Shiny new and old wires. Well finally i saw evidence of backfeeding after in desperation i switched the Two Yellow feed wires to the coil and wiper motor. Looked at the inside of main connector at fuse box and shook my head at the black coating of windshield butyl rubber all over the pins... Some Einstein packed in and thought this might protect, but melted inside and screwed up all. Explains the pathetic sound of buzzer and horns and more that can't work right like this.