AADConnect only logs the information/warning/error messages as stated here.There are no separate AADConnect log files outside of event viewer.

Having done some testing, and some further googling the view i have come to is: If it relies on logging to event viewer only, then is there any guidance or documentation (i haven't managed to find any) to identify which event IDs would correlate to the above activities, trawling the logs so far i havent found anything identifying when a connector has been changed or, frankly, when an admin has opened or used the tools (MIISClient or Azure AD Connect app/tool) It seems odd that there is no evident admin audit log for something as critical, and security sensitive, as AAD Connect, if there isnt. I am seeing a lot of clients systems whereby AAD Connect spends a lot of its time complaining about the need for an initial sync, I suspect a lot of these cases are where an admin has opened the sync and OK'd, or even cancelled out, but it seems to have marked the connector as changed. I'm looking for something that logs when an admin has, for example, made a change to the sync, such as adding or removing an OU from the sync scope, manually triggering an initial or delta sync, opening the admin tools or opening the connectors in edit mode? For more information, see Archive Azure AD logs to an Azure storage account.Does anyone know if there is an Admin audit log for AADConnect? You can retain the audit and sign-in activity data for longer than the default retention period outlined in the previous table by routing it to an Azure storage account using Azure Monitor. For security signals, the collection process starts when you opt-in to use the Identity Protection Center. If you don’t have any data, then it will take up to three days for the data to show up in the reports after you upgrade to a premium license. If you already have activities data with your free license, then you can see it immediately on upgrade. The first time you open Azure Active Directory or use the reporting APIs When does Azure AD start collecting data? Azure AD Edition In this article, you learn about the data retention policies for the different activity reports in Azure Active Directory (Azure AD).

Aad logs