Sharan won't turn off!

[Daniel Watson]

Hi,
I am looking at purchasing a very well maintained, cheap sharan, a bit rough around the edges, but has an electrical issue that has me stumped.... wondering if you guys may know the answer.... A 54 plate 200k asz 130 tdi.
I took it home for the weekend to give it a good going over
when I come to turn the engine off, often the engine will stay on, and the hand brake light, odometer are all still on sometimes if I blip the throttle it will all go out and that's it, other times I have to re insert the key and turn it off a few times, other times it will turn off as normal. And some times the engine will turn off but the dash lights flicker on and off, on and off and continue doing that for a while.

everything appears dry, I. E. No water ingress. The underbonnet fuse box (alternator) is a bit crusty and melty.  It recently had a new turbo, and inlet cambelt kit etc and wonder if an earth or live has become dislodged... or even if it could be a relay

It has had a new ignition switch, but not fixed the issue...

is this anything you have seen?

[johnnyroper]

I would check the usual suspects of door wiring first they can break and short out potentially energising circuits that should not be.
if they are ok I would be looking at relays that energise with ignition on or the control unit in fuse box.

The battery fuse box will cause electrical issues like not charging but doubt it would cause unable to switch off,would still need sorting mind