Wiper Blades

Hi All
I have a couple of small problems. 53 plate TD4
1/ When I use the wiper on single wipe they some times stop befor the have returned to to their home postion. what is causeing this? how can I fix it?

2/Slight problem starting. Glow plug light never shows (not even for a second) car starts just the almost dies but picks up again. No problem once it is running. Do I need new glow plugs befor winter sets in?

3/tailgate lock is sieged rear window con only be full up or down. best way to free lock?

Thanks for any help

M

auto park culd be faulty [this werks on earth return in the wiper motor g/box . . . .glow plug time out will only show at around 5deg [its a fast start system [yes check yer glow plugs as one could be u/s] if so change em all. . . . .fergot wot the last wun wez hope this elps earthling