WASHINGTON – Mack Trucks Inc. is recalling 240 Mack LEU and MRU trucks built to operate on compressed natural gas. On these vehicles, the alternator ground cable runs directly to the starter, which defeats the circuit protection.

In the event of an electrical short, a vehicle fire may result, the National Highway Traffic Safety Administration reported.

Mack will notify owners of the recall, and dealers will relocate the alternator ground cable to the engine ground stud. There will be no charge for this service.

The recall is expected to get under way at the end of this month.

Vehicle owners can reach Mack Trucks at (800) 866-1177.