I replaced the radiator fan motor today and ever since the idle has been either surging or constant between 1k &2k. Before it was solid at like 700. I have no idea what they have to do with eachother. I tried resetting the ecu by undoing the battery for a few minutes, but that didn't do anything. Do I need to have the battery undone for a specific amount of time to reset the ecu? Other than that what can I do about this?