When running a map from Great Plains to CRM, all the records in CRM are being changed to the same thing
For example, running an Accounts mapping from Great Plains Customer. When you run the map, every account that gets created has the same name and Customer ID (typically the last one in the source file) This indicates that a key field was not selected in the CRM mapping window. Since Great Plains and CRM have different key fields, you need to specify which Great Plains field is your key field in CRM. For example if you are creating a Great Plains customer to CRM Account mapping, you need to check the “Key” checkbox next to CUSTNMBR on the left side of your mapping screen. This applies for any import into CRM, you must specify the key field in your source file, otherwise the records will be duplicated.