Not starting jetta 2l diesel

[Patters78]

Gents

My missus car just broke down it's been difficult to turn over for a few weeks but usual does
Anyway she went to the shop and went to start it nothing not clicking lights on dash all ok.

I turn up hook my car up via jump leads 30 mins later instead of nothing I'm getting one click
And I had to leave it to go to work

30 mins on leads and no start?  To me it seems as tho the battery was flat

Any ideas

[Ricky123]

Could just be the starter motor... but first thing I’d do is get it plugged in and see if there’s any error codes present