The remote failed for the fan[I] for sevearl weeks, then worked once when I removed the housing which holds the receiver unit. After it would not work after this initial operation, I switched receivers and remotes with another fan that also has a light. After plugging in the swapped receiver the light works when powered by the weall switch , but the remote will not control the light or the fan ]

Remotes and receivers have codes installed via small dip switches. You need to check to insure switches in both units are an exact match. Moving a dip switch between O and I , even for just one switch will stop it dead. To make it easy move ALL switches to O