Spartan Motors Inc., a supplier of diesel pusher chassis to motorhome manufacturers, will expand its ambulance business with the construction of a new, $4 million manufacturing plant in South Carolina.

Spartan’s Road Rescue Inc. subsidiary will build the plant to increase output capacity and expand its offerings, according to Chuck Drake, president of the St. Paul, Minn.-based company.

Construction of the new 100,000-square-foot facility in Marion, S.C., will begin during September and it should be ready for occupancy by January.