Depends, if you are getting a whole new cluster from a junkyard.....with different mileage than your car has then technically yes. It'll have to be programmed to have your cars mileage. There's services on ebay where you send your cluster to them and they change the mileage to the correct mileage. But this isn't necessary if you don't care if it has the wrong mileage. You can plug it in and it'll work just fine. If you are just unplugging it to gain access to something else and are plugging the same cluster back in....you dont have to do anything.
Does the cluster have to be reprogrammed after installed or just plug and play?
Depends, if you are getting a whole new cluster from a junkyard.....with different mileage than your car has then technically yes. It'll have to be programmed to have your cars mileage. There's services on ebay where you send your cluster to them and they change the mileage to the correct mileage. But this isn't necessary if you don't care if it has the wrong mileage. You can plug it in and it'll work just fine.
If you are just unplugging it to gain access to something else and are plugging the same cluster back in....you dont have to do anything.