Breezy_Pete

Remove cabin fuse #7 and clean the contact surfaces. Then put it back in, noting if it feels loose. Then if the problem still happens, check the flat strip fuses in the fusebox above the battery. The power steering fuse is a 50 (or maybe 60?) Amp one with the thicker of the two red/black wires going to it. Examine the metal strip very carefully for cracks, photograph and post here if unsure. If you do find fuse 7 is dirty, corroded or loose, you should probably also find the fuse for your turn signals and look for similar corrosion, since that is also reported as an intermittent fault.

The only other part number that explicitly says for CBZA, CBZB engines without start/stop (which I assume matches your requirement) is 03F 903 023D, which is a 140A Bosch item. May be worth broadening your ebay/scrappie search to include that one.

I expect there's quite likely to be other versions including same or lower rated ones, perhaps a 110A Bosch that would fit. Will have a browse of the parts catalogue next time I'm upstairs near the 'big internet'.

The Bosch one can surely be refurbished, but it's not a quick and easy job, especially the first time you try. A few youtube vids exist, showing what's involved. I've done a couple, one including slipring change IIRC, back when I had bags of spare time. Doubt I'll do another. We seem to be on a bit of a parallel path. The one I tested on my Polo today was that same 03F...E part number, bought from ebay, but I need it to replace a broken one in a car I hope to buy tomorrow. Noticed that the back cover of these Valeo versions don't have screws or nuts holding them on, just plastic fingers that slide down threads, making disassembly more difficult. Parts catalogue actually says that the regulator/brushpack is a 'no replacement part available' from Skoda. Possibly because of these push-on fixings for the cover. Higher price for the reg may be just down to selling fewer due to this apparent 'harder to service' design.

Yep

Update 21/03/25 Audi going very nicely now, with the exception of a rattle that's almost certainly related to the one MOT advisory, front upper arm play, both sides. Nearly got a quote for getting this done, as it's all a bit 'heavy engineering' compared with what I'm used to. Fruitlessly changed a hydraulic engine mount on Wednesday, just in case it was that. Test drive filled me with joy for about 1 minute after that and then the rattle/clatter was there again, unchanged. 😆 Now there's a likelihood that both my Polo and the A4 will be going, in favour of a Roomster that I'm going to see tomorrow. It's like a blend of the two, in terms of size and shape (and mass). 😁 Petrol, turbo, blue, and something of a fixer-upper; why wouldn't I want that?

Most bolts that people think are, aren't. Angle tightening after a lower initial torque is simply a far more accurate way of tensioning fasteners than torque alone. Friction makes up so much of the torque 'resistance' that it results in highly variable fastener tension. Angle always results in same increase in tension, because the extension of the bolt is a fraction (e.g. 90/360) of the thread pitch.

Please message me if you still have the original motor @DJNafey , I may wish to give you some money for it.

No VW group part number to be seen? That number looks like just the brushpack/voltage regulator part.

Keying of connector looks right for both original Bosch and Valeo alts here. Perhaps that 140A alt really isn't 'drop in' compatible with your car, what part number does it have?

Might be room to hammer one or more of them looser for removal, depending on how crowded the engine bay is near the bolt heads.

Couldn't hold it all above open vice and take photo, but hopefully you get the 'drift'.

There's a trick with the lugs. The steel threaded bush is actually a tight but sliding fit within the inner alloy lugs. Before attempting to fit, you can move these outwards to increase the gap down the middle. Doesn't help with removal, but knowing it can make refitting much easier. Put bolt in several turns with it off the car, supported around a hole in something that the bush can move into (e.g. open vice jaws), then give the bolt head a few taps with heavy hammer. Only needs to move a mm to make a world of difference.

Strangely enough, I was planning to test a Valeo alt in my Polo at lunchtime, and I'm pretty sure the current one in there is a Bosch, so you may have saved me some headscratching if the connector doesn't fit.

Yes, I can confirm that pin 1 is the blue wire. Interesting that the keying is different, I shall try to remember that.

The insert helps to retain the contacts, I think. checking pin numbers for you now, but I expect that's right.

Not true, unless the car has start/stop technology, which I doubt, or the replacement one was the wrong type. Where did you get it from? Any photos from listing etc.?

Keeping my fingers crossed that the fault doesn't come back after all that. Is that oil pressure switch plug fully on? Or is that an extra-long switch? It looks odd?

Is it the twin cam or single cam 1.2? (Spark plugs vertical down centre of head in the former, angled out the front in the latter)

Or the timing chain has jumped. That fault code isn't one that Google recognises. Please check for typos.

Google images will show you lots of graphs of voltage versus lambda value and/or air/fuel ratio. Does VCDS not show you some fault codes in engine ECU? Emissions (picture of engine) light on?

Either should be fine. May not find new ones of the old part number though.

Is there maybe a washer left behind stuck to the gearbox from the old switch, which is making the distance wrong for the new switch? If that isn't the probIem, I would get a genuine new switch, personally.

Yes, measure for volts on blue wire contact of alt plug with ignition on.

Can you see markings next to the two way connector on the Bosch alt? Should say L and DF, I think, if it's the correct type.