Breezy_Pete

@ThomasP will be more likely to see your request now that I've tagged him but, @svims best if you let me know the VIN for your car. That will allow me to look up the coolant temperature sensor wiring info that's most appropriate, which is not necessarily the same as on Tom's car.

Reg or VIN please, to find build date and thus the best circuit info. Any chance you crossed over some same or similar-coloured wires when repairing loom?

A/C mediated fan action tends to be triggered by refrigerant pressure levels, not engine coolant temperature. I suspect your fan control module may be built into the radiator fan. Let me know the VIN if you'd like me to investigate.

Everything on our Roomster went to sleep with door open and no attempt to lock car. Surprised me a little.

More chance of getting the road signage made more standard, I should think, and good luck with that!

Very unlikely to be there.

Does any water emerge when A/C is doing its thing?

Is the insulation not subtly perforated, like the edge of a stamp in a sheet?

Dunno, maybe the weld has cracked between pipe and sensor fitting?

Warrior makes a good point. I spent a lot of time over the BH weekend assuming I had a parasitic drain on our Roomster, but found nothing, except a failed (very recent) battery. To let the car shut down I found that just letting it sit, for around 15-20 minutes, after opening the door for access to cabin fusebox, was enough for the few fuses showing mV to go to zero.

No problem. Bear in mind the the diagrams in the link are for LHD car, so your drain will be the other side of the matrix hoses.

Firewall, engine side, next to matrix (not refrigerant) pipes, hiding under a flap of sound insulation. See this thread: https://www.briskoda.net/forums/topic/514260-air-con-leak/

There are two fuses for instrument cluster, an ignition switched supply from fuse 6, and a permanent supply from fuse 39 (on your car, not on earlier models). Fuse 39 is also a permanent supply to the steering column control unit J527. Thin red/yellow wires for both destinations. Beyond my patience levels to define exactly all the fuses for any given individual car. Could probably be done, but would take hours with the resources I use (in this case a 4140 page pdf of all the possible electrics in an Octy 2 from May 2007 - April 2011; plus build date and a list of PR codes from your VIN). What steps have you taken to assure yourself that the car is properly 'asleep' before these measurements are done?

Let me know the VIN and I can find out what that fuse does.

First start after the change will be noisy, while it fills with oil, but subsequent ones will hopefully be better.

Yes, that's it,and that's what I did. I did try to squirt a bit of clean oil into a hole on the side of the new one, but I don't think much, if any, actually went in.

Look over the top of the engine to find the green oil pressure switch. Tensioner is just below it, red arrow points at the 27mm hexagonal back end of it. Unscrew, remove rearward, put new one in, tighten to 60Nm.

Yes that has the later chain type. Tensioner part number is 03F109507F (price of this part from Skoda in UK is approx £75). There are some coolant hoses a little obstructing the access for changing it, but I found it possible just by pushing them aside. Requires a 27mm socket to undo the old one, remove, and tighten in the new one. Specified torque is 60Nm.

Yes, it might. I think your car should have the later, duplex chain, which is less likely to itself be a problem. I can't remember right now when the later chain design started to be fitted in mk2 Fabia, but I could check for you tomorrow with VIN number. If the car has had regular oil changes with suitable oil and filters, I doubt the oil pump would have problems. Don't know anything about the high pressure fuel pump, yet.

Has the chain tensioner ever been changed? Cheap and easy thing to do first, if not.

This evening I'll edit this post into a big version, but a spoiler is that it was addressing the oil leak, quite a significant one, mentioned on the last few MOTs as an advisory "oil leak front of engine". I'd already guessed at the culprit, and even headed down to the car on my first visit armed with the necessary gasket, since the replacement involved alternator removal amongst other things, and I thought it would be nice to 'kill two birds with one stone', while I was fitting a good alternator to get the car mobile anyway. I posted a video of the seal replacement in a related thread after doing a search for 1.2TSi oil leak on here, and coming across this thread: https://www.briskoda.net/forums/topic/438119-2011-12tsi-dsg-oil-leak-head-gasket-gone/page/2/#findComment-5931213 Typically in that vid, the lambda sensor removal is made to look much easier than ever happens in real life, in my experience. It does have to come out in order to get the heatshield off, annoyingly, which then gives access to the right-most screw that holds the filter/cooler/alternator bracket casting on. Wildly underestimated the work involved, and didn't even contemplate it on that occasion. Spoiler: this figure of 8, plus another loop, rubber gasket seals the casting that holds oil filter and cooler onto the front of the block. It had stopped sealing it. The rubber was hard as a rock, squished flat with no compliance left at all. Can't blame it at 13 years old and 159k miles driven. Not the best design, possibly. There were also a few tiny bits of casting flash around the edges of that face where the seal sat, maybe holding it off the block a smidge more than planned. Tidied up before new gasket was fitted.

Next was a couple of electrical fixes. Partner had told me that high level brake light was inop, following me back from collecting the car. I'd noticed that the passenger side wing mirror was pointing down and inwards at an unhelpful angle, and the adjustment didn't work. Boot wiring problem was unsurprising. Previous repair evidence on a few wires, and one newly broken wire responsible for brake light non-function. Easy fix. Mirror fault was imagined to be similar, and sure enough, after minor battle to release the bellows from (right) A-pillar 28-way connector, a couple of broken wires greeted me. Don't seem to have pics, except this one, taken just after loom removal and before bench repairs, to remind me the shape/profile of the loom as it comes into the innards of the door. Repaired wires restored function of the mirror, and I did a couple of other wires that had cracked insulation but no sign of strand breakage yet, splicing lengths of super-flexible silicone insulated wire pre-emptively. Was glad to discover that the loom removal and refitting process wasn't too bad to do. Had cause to inspect the other (passenger) side at the weekend and there were two wires with cracked insulation but none broken. May get round to future-proofing them at some point when everything else is done!

Part number suggested by Parts Catalogue is 5J0 971 120 HD, RRP is currently £138.50 + VAT. Nicer prices at LLL Skoda Wiring Set For Door 5J0971120HD - LLLParts I repaired the loom on our Roomster recently, but by taking the whole thing out to repair on the bench. Probably worth persisting with your soldering efforts, extending the wires is a good plan.

I've just sent you a private message Robert. 👍

Message me with VIN if you'd like me to look up part number of door loom.