M-Sport managing director Malcolm Wilson has admitted he is concerned by the so-far undiagnosed electrical failure which halted Ken Block's Ford Fiesta RS WRC on the Rally Mexico opener last night.
Block starts the event proper this morning with a 10-minute penalty after failing to make it through the half-mile street stage in Guanajuato last night. The American's Monster Fiesta was returned to service in Leon and worked on until one o'clock this morning as the Cumbrian-based team attempted to find out what the problem was.
"I'm very disappointed for Ken," said Wilson. "We changed the main chassis loom and all the electrical components, the ECU, and everything, but we couldn't find out what the problem was. We still have no idea what made the car stop and obviously that's a concern."
Wilson's M-Sport firm is running nine Fiesta RS WRCs in Mexico, including the two factory cars. The precise nature of the fault will be discovered when the car is returned to Britain.
"We can plug the [wiring] harness into the machine and it will tell us everything," said Wilson. "It's just so frustrating having to wait until then and, obviously, really frustrating for Ken to be starting with a 10-minute penalty – that's not satisfactory at all."
Block's Ford had suffered a minor electrical problem on the shakedown stage yesterday, but the team said that was unrelated.