The plant was already going to be on regularly scheduled holiday break Dec. 31 and Jan. 1.
Unifor didn’t say why the plant would be idled for the additional eight days and neither the union nor FCA immediately responded to request for comment.
FCA previously shut down to adjust inventory in October and January of 2018.
About 6,000 workers at the Windsor Assembly Plant build the Chrysler Pacifica and Dodge Grand Caravan on three shifts a day.
Pacifica sales in the United States are up 2.1 per cent to 109,386 units through November. Grand Caravan sales are up 20 per cent to 142,233 units.
Sales aren’t as strong in Canada where the automaker has sold 30,592 Grand Caravans, down 30 per cent from the same time last year. Pacifica sales are up 4.5 per cent to 5,794.
The is a 91-day supply of Pacificas and a 29-day supply of Grand Caravans in the United States as of Dec. 1, according to the Automotive News Data Center in Detroit. Similar information about Canada isn’t available.