not being a TD5 expert! my buddy has 2005 def td5. New battery fitted recently, the engine wont turn over, only clicking noises heard.
-disconnected the trailer, bingo, it started first time! WTF!? (however, the clicking noise stays with engine running!, most annoying)
I seem to remember the 300tdi needed a flasher unit upgrade when using a trailer.
-Does the TD5 need a similar change?