Single forum is the way to go,the more folks who browse that one forum,the more replies you can expect.
When I recently purchased my '98 E300 for a favorable price there existed a host of electronic issues and failure codes that frightened the former owner no end,not to mention the dealership's pricey quotes for service.
However by posting questions and most importantly searching the archives I have successfully solved ALL of these gremlins{for the moment,anyway}