The first issue if you are doing things in the order you specify is that you cannot disconnect first and then subsequently reconnect. The reconnect API must be called with a valid access token, as the current access token will be invalidated and a new access token will be issued.
Secondly, there is a window for calling this API to refresh the 6 month life of the access token, it must be called in the last 30 days. This allows your app to refresh the token without prompting the customer again.
However in all cases if you disconnect, or the customer manually disconnects you cannot call the reconnect API. You need to take them through the authorize flow again.
hope that helps
Jarred