General Motors Corp. and Ford Motor Co. on Monday issued recalls affecting about 764,000 cars and trucks. GM said it was recalling about 414,000 1991-model Chevrolet Cavalier and Lumina, Pontiac Sunbird and Grand Prix, Buick Regal and Oldsmobile Cutlass Supreme cars to inspect guide loops for shoulder safety belts. The company said a small number of loops may be cracked, which could affect shoulder-belt operation. GM said it was aware of no injuries attributed to the problem. Ford said it was recalling about 350,000 light- and medium-duty F-Series trucks, Broncos and Rangers because of a potential problem in door latches. The company said if water leaked into the door-latch release mechanism and froze, the door could appear to be latched when it actually wasn't. Ford said it was unaware of any accidents or injuries linked to the problem. Inspection and repairs in both recalls will be performed for free.