In this Sept. 27, 2018, file photo a United Auto Workers assemblymen work on a 2018 Ford F-150 trucks being assembled at the Ford Rouge assembly plant in Dearborn, Mich. The United Auto Workers union wants Detroit's three automakers to shut down their factories for two weeks to keep its …

Source: JOHN CARNEY

Ford has slammed the brakes on assembly lines at two key factories as the U.S. automaker struggles to get back on its feet following a two-month long coronavirus shutdown.

Ford stopped the assembly lines at its Dearborn Truck Plant on Wednesday afternoon after a worker there tested positive for coronavirus.  The Dearborn plant makes the Ford F-150 pickup, the companies biggest money-maker.

The Dearborn closing follows the closing of a Ford plant in Chicago on Wednesday morning after one of that factory’s workers tested positive. The Chicago plant makes the popular Ford Explorer and the Lincoln Aviator SUV.

The company began to relaunch assembly plants on Monday, promising to keep workers safe and to closely monitor for signs of infection and quickly test workers. The company said that it believes the workers were not infected at the plants but arrived at work with the virus having contracted it during the shutdown.