There is not a Haynes for the Dispatch unless it has just come out. Email me the details of your engine and I'll see if I have a diagram that will help. This would have been a good response but this site does not allow email addresses on replies. Ah well....
Try here... http://www.emanualonline.com/Cars/Citroen/Citroen-Dispatch-Workshop-Manual.html.
you can get a copy of the official citroen manuals. I warn you it's a huge set of files and requires a complex set-up procedure. I think it cost me £12 or something like. The information is alarmingly sparse, I can only think that they assume their mechanics have been trained to know all the basics of their cars (HAH!) However there are some good diagrams which have helped me a bit in my adventures with my Dispatch.
Steve
Steve Jones, January 2013