Breezy_Pete

Yep, Ah is actually less critical than the Cold Cranking Amps (CCA) figure in terms of getting a diesel going, so if all else is equal between a couple of candidates you're considering, pick the one with the higher CCA figure. Bear in mind that there are multiple 'standards' for measuring this which result in different figures so ensure you compare ones with the same authority e.g. DIN.

Diesel or petrol engine? If the former, then something towards the top of that Ah range, if petrol less critical.

A quick look at wiring diagram says the Golf4 set-up is quite a bit different to what I'm used to, so the lock motor control is going to be local to the 'driver's door control unit'; presumably where any relevant relay is. There is a central convenience control unit somewhere, but the door locks don't have any wires going directly to that, so presume that is mainly doing RF remote receiving and alarm related stuff. Tempted to acquire a cheap ebay door control unit of this type for educational purposes. Does the car have electric fold-in mirrors?

I haven't delved into mk4 golf electrics, but on Polo 9N and Fabia there are separate relay coils/contact sets for each door, so I wouldn't rule out relays yet. Will look at circuits and parts listings tomorrow. What year is the car? Sorry, dumb question, you said 1998 in the first post.

Haven't fully digested that story, but I would suggest that the current supplied to the motor may be reduced if the relevant relay(s) in the central convenience module have 'tired' contact surfaces. Dirty/corroded contacts between connector pins on the way to the lock could have additional losses. That reduced current might affect the behaviour of the motor and lock mechanism. I'll have a better read of your info in the morning. Changing out a few relays may be well worth doing before buying and trying any more locks.

Good shout, looks like the tip of a screw coming through the bracket to the left of the other one. Wondered what that was when I first looked, but didn't put two and two together. Thanks goodness one of us has a useful answer.

T45 Torx bit plus plenty of lever arm, I'd think?

Looking at a few of the parts diagrams here, the answer appears to be no. LLLParts

Did find o-ring, it's been around in a drawer for a few years but you can have it for postage plus a couple of quid if you want. PM me if you like.

I'm not familiar with the breather system in your engine, sorry. I might have a spare sensor o-ring in my shed though, will look shortly.

As an aside, it'll be worthwhile checking that your breather system isn't blocked somewhere causing excess pressure in the crankcase, leading to this leakage. If there is such a blockage or malfunction, other leaks will probably appear if not sorted. There's no obvious (to me) other reason why an undisturbed o-ring should start leaking in a low pressure application like this. I suppose if the sensor has been changed at some point, and the o-ring not changed with it, that would be an unsurprising cause of the leak.

Looks like you'll need item 1 from here which is the o-ring: switches and senders on engine - Octavia(OCT) [EUROPA 2005 year] (7zap.com) PN - 038103196 You don't mention what year or engine code your 1.6 FSI is, but I'll take a stab at this being the right one. Can check again armed with that extra data if it isn't that. See my signature if the term 'engine code' is a mystery to you.

It's done. 😁 That video was perfect and made that bit extremely easy to sort out. I was so chuffed that he'd made the vid that I sought out a phone number for him and called to thank him. Some free publicity to add to the video link: web address - dutchbikeshop.co.uk, Tel: 01903 730089, based Littlehampton, Sussex. He will be getting any future business to do with this bike for sure. Took me a while to figure out putting back and adjusting some of the other bits like the chain tensioner/wheel centraliser bits, and the flipping 3-piece plastic chainguard. It is a 7-speed version as yours above Lee. A few photos of the closing stages.

We will never know obviously implies that we don't already know!

Depends what that thrashing and abuse is, versus what the algorithm gives a damn about. We'll almost certainly never know.

There's no pressure sensor, but simply a pressure switch (open circuit when pressure is below threshold, short to ground when above). Test the warning system by unplugging the single wire connection and driving the car, expect red warning light above 1500rpm if not before. Location:

Could be informative to get @Aspman's latest thoughts on his heat pump installation as unit prices are heading skywards.

Sensor in the sump just measures level and temperature of the oil. It can probably feed into an algorithm that infers things about probable oil condition using oil temperature, ambient temperature, total run-time since last change and journey durations, I guess. Probably rather a crude 'guestimate' though.

Salvation is at hand: 🕺

This may be a key picture, which I should have hit up youtube with yesterday: Apparently it's a Shimano Nexus system.

I was fixing a rear wheel puncture on my partner's bike yesterday, and opted to replace the inner tube rather than patch. This meant I had to remove the rear wheel, which was much more of a mission than I'm used to. It has hub brake of some sort on one side, which I did managed to disconnect the cable of, and this gearchange thing on the chain/other side. There was probably a way to disco the cable and leave it in place, but I thought I'd dive in and start undoing/removing the bits and pieces with the yellow markings on. This went well in terms of disassembly... ...but had me close to tears when I went to try and refit it afterwards. The image is with things just loosely in place, not locked in properly. Had to put it away unfixed before it had me smashing things up! Anyone got experience of this type of thing, or even know what the gear system is called, please? It's a Dutch city-type bike I believe - won in a competition - haven't got the name of it on me, but can ask the missus to have a look in the shed if helpful.

Sorry for slow response, was out and about by the time this came through. As far as I can see this wire is only to do with the electric mirror heating and adjustment switch, so I'm a little surprised that its breakage caused a window motor problem. It comes from the onboard supply control unit (above acc pedal on RHD), connector XP3 pin 1 and terminates at the 10 way connector of the mirror adjustment switch, pin 1. What can happen with window motors that are on the blink is that depowering them for a while and then reconnecting the main permanent 12V feed can kickstart them back into proper operation, temporarily. You may have done this incidentally while fixing that wire break? I hope this isn't what you have seen, as that may result in disappointment again soon, but at first glance that seems likely to me. Edit: unless...there's a chance that you mis-remembered and it was actually a black/blue wire, in which case that would explain the problem, as that's an ignition 12V feed that acts as on 'wake up' input to the window motor module.

Which of the connectors at the a-pillar and what pin number? Photo? Sounds like good progress though, well done.

The battery management system will almost certainly figure out all that it needs to without any coding, it may just take a little longer than it would with the coding input. See this post and the link within: https://www.briskoda.net/forums/topic/499676-battery-causing-various-errors/?do=findComment&comment=5607340

I suspect the position of the module is very similar, but see if UrbanPanzer's info makes more sense than mine. It should do, but the diagram doesn't look awesomely clear to me.