The blue-slate-slate wire is 5VDC and the white wire is the ground. IIRC the big black cap (C1) on your CPU board connects directly to those wires so the ground wires go to the pads that connect to the ground on the cap. The 5VDC wires connect to the other wide pad. Great Plains Electronics should have the connector you need to replace A1J1.
Steve
System 80, not just a job, it's an adventure