Posted a thread about a month ago - tailgate would not open, then rear wiper not operation, no revwersing lights or rear fog light. Looked insie the SAM unit in the tailgate, board black. Purchased a used unit from smartpartz, fitted everythin working, until wife a Tesco opened the tialgate before I had unlocked the doors with the remote. everything working except the locking mechanism. visited my local garage whoc sonnected to STAR, lock seemd to be open circuit so purchased a new one - no difference (just anothe £200 pound lighter). does the unit require pairing to operate from the remote?