truck does not turn over on 1990 Ford E-350

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
engine was cranking, voltage shows 14 plus volts, then it faded to nothing - smell of plastic, now no crank
(2) Answers
You need to replace both batteries and check all battery cables and connections. don't replace the batteries with cheap batteries.