Check the metal spring-sockets that are inserted into the plastic housing of the wiring harness. I found on mine that the little tab that is supposed to keep the metal contact from backing out did not engage the slot in the plastic housing. When the connector was plugged onto the header, the socket got pushed backwards and made poor or intermittent contact.
I pulled the socket out of the housing, bent the tab slightly and re-inserted it. It held solidly after that.
N5IB
