Hello. The key on my son's Golf mk4 will not enter the hatch boot lock. Have tried to free with WD40 but will not enter the barrel. The alarm. electric window, interior light, and boot light circuit now blows the fuse. Have checked the wiring to the doors and boot but cannot find any breaks. Have taken off the boot fairing and cannot see any signs of leaking from the wiper tube or corrosion. When my son fits a new fuse the system is ok until he opens the boot, the alarm sounds and fuse blows.

Is it easy to replace the boot lock, can I keep the same barrel, will the lock have to be coded ... if I remove the lock should I beable to free the barrel so that I can once again open the lock manually with the key. Would appreciate your help as my son has had to replace the dash because the immobiliser unit failed... after that expense I hope to solve this problem myself.