Hi Harry,Sounds to me like you've identified the problem, so 1/2 of the deal is done. At least you know the cause is a bad connection. Now the matter is what to do to solve it.
Where is the connection that you've cleaned? What's to stop you from simply re-wiring? I think I'd be most comfortable with that solution. Just in case the problem was caused by an open inside a wire, probably as it enters a crimp connection. You could be moving that when you clean it, making it work for a little while. If you can re-wire, that will replace both the connector and the wire.
Wayne