Breezy_Pete

Do check the pressure reading with just ignition on. If it reads about 6 bar, and the same when engine is running it chucks my 'low on refrigerant' idea in the bin.

M6 x 45 Allen head with a flat washer by the looks of it; first of the item 8 parts? vacuum system; exhaust gas recirculation - Fabia(FAB) [EUROPA 2005 year] (7zap.com)

Maybe, maybe not. You may just be able to remove the top or bottom of the cowling around behind the wheel? That might give you visibility of the connector.

Diode is 1N5408 by the looks of it. That's a numeral one at the start, not a letter 'aye'. Pennies to buy. Can't explain the sequence of events just now.

I bet they knew this was the problem, because they've seen it before, and they would know how extensive the resulting damage is.

Reason I mentioned start/stop is that obviously if that were in use/fitted it would make the starter solenoid activity much more frequent.

Yep, the brown/violet is an earth connection, and that diode must prevent conduction from the wires connected to its other end. The diode must be within that heatshrink tube that you've labelled '2'. The lump in the middle I think. I bet that's what's failed, causing positive to chassis shorts. Do you tend to let start/stop do its thing, rather than disable it each drive?

I think the edit is there for everyone, but only for a short while after posting if you don't have Freedom. Possible that it only appears after a qualifying number of posts though? Have a look in a couple of posts time, in case it is 10.

The brown/violet coming down off J811? Has the diode failed short circuit, I wonder? That would be horribly ironic, as I think its purpose is as a so-called 'flyback diode' to stop reverse-voltage spikes from the starter motor solenoid causing bad stuff to happen to connected electronics.

I'd expect the onboard supply control unit to be just above the accelerator pedal, I think.

I can't see a violet/yellow wire in that wiring diagram?

I know it's minimally relevant to legality or otherwise, but MOT doesn't care about supplier details: 0. Identification of the vehicle - MOT inspection manual: cars and passenger vehicles - Guidance - GOV.UK (www.gov.uk) You do not need to inspect the following items: the supplier’s name postcode BS number logos or emblems outside the minimum margin around the registration number

Ah, yes; good point about checking pressure when not running too.

6 bar high side pressure when running would suggest low refrigerant level I think? The system is intended to be sealed, but they do leak in time.

Tricky to know whether it would be doing any good, or harm, or nothing.

I don't know really, but excess crankcase pressure I suppose. Different engine, but have a look here:

No; very unusual. There may be an underlying problem that is causing them to fail.

Find out which wires coming away from the stalk are normally earthed by this switch, and fit an external momentary push switch that can earth one or other of them.

Does either fan spin?

Logically, the single bolt end, but I would invite confirmation from Superb owners who've removed one. Seems likely that there's a captive nut in the A-pillar, but I can't promise you that with any confidence. That's an XZN tool fitting, not a Torx, by the way, just in case you didn't know.

Door removal covered incidentally here: Skoda / VW worn door hinge fixed without removing the door - YouTube He doesn't remove the door, but shows/removes the grubscrews which he mentions as being E8 skt. You would just loosen or remove those grubscrews then the checkstrap then lift the hinge halves apart. Repeating warning about weight of door/ 2 person job, if you do opt for removal.

Not sure how/whether this video fits into this, but plenty of comments querying the connection Piston engine with eccentric connecting rods. - YouTube

Credit to @e-Roottoot for predicting that this might be a very dodgy investment opportunity. I've edited my initial post to include links to some heartily critical videos referencing the one I linked to. Alfadan have just started another crowdfunding round here, and currently the comments at the very bottom of the page include one from Joseph L. linking to the second of those, asking for response. Not sure how long that'll be there but it's stood for 8 hours so far. The Workshop fella has now put up a third video What a scam looks like - YouTube Reminding me a bit of that electrolysis miracle thingummy 'ezero1'; except my instincts were sharper on that one. Might be that the intro stuff about secondary imbalance was a genuine learning experience for me in this one, which put me in a receptive mood? Cunning.

I meant J.R. with his analysis, sorry!

^ Good work.