Slowing demand sidelines 1,300 workers as Factory ZERO shutdown stretches into April.General Motors will keep its main Detroit EV plant closed as it demand for its electric vehicles remains slow.The automaker said Factory ZERO will remain quiet through April 13, extending a shutdown that began March 16, reports Automotive News. The move temporarily lays off about 1,300 workers at the plant, which builds the Chevrolet Silverado EV and GMC Hummer EV.GM called the decision a necessary adjustment. Production at Factory ZERO has been up and down over the past year as the broader EV market cools. GM cut production by roughly half earlier this year and has since reduced shifts and reduced battery production. Reports indicate thousands of workers across GM’s assembly and battery operations have been affected by layoffs or furloughs.This latest pause comes many automakers reexamine their electric vehicle strategies as regulations continue to shift and consumer interest wanes. GM has already reported $7.6 billion in writedowns related to its EV programs.At the same time, the company is looking more to its money makers for a financial lift. GM confirmed plans to boost production of heavy-duty internal-combustion trucks at a Michigan plant starting in June.