A sales rep drives across country, after a while the engine dies on him.
He opens the bonnet and looks to see if there's anything obviously wrong, but can't see anything wrong.
A few moments later, a voice behind him says' check the fuses', he looks round, there's no one there, the road is deserted except a black horse in the paddock beside him.
He turns back to the car and thinks 'might as well check the fuses'.
Sure enough, he see's the main fuse has blown, he changes it and starts the car, he drives off a happy man.
He decides to stop at the local pub and have lunch, as he waits he tells the barman his story.
The barman asks "was there a black horse in a field near you?"
The rep says "yes, there was!"
The barman says " well your lucky mate, there's normally a white one there and he knows bugger all about cars".