Check the main harness under the power distribution block beside the battery.It is a heavy harness that splits into a Y.Untape it at the Y,there are three wires crimped to one wire,think they are red and white but can't remember for sure.The connector was prone to coroding,sometimes made contact,sometimes didn't.Whether it's bad or not,remove the connector,solder and heat shrink the connection.If that is not your problem,it will eventually be one.