Breezy_Pete

The car doesn't have start/stop.

I can send you airbag wiring info for your car this evening if no-one else does first. I'm on the road for the next few hours.

If you have a place where you usually take your cars for MOT, I would pop in and ask them. I suspect that if all lights (including number plate lights?) are OK, that the warning light cannot constitute a reason for failure. I believe that the 'common wisdom' that 'any warning light is a fail' is simply an urban myth.

Have now ordered an aftermarket new 140A one from Ebay/ Schmitz Rotary in Birmingham, should be with me at home on Mon/Tues. We'll borrow Dad's car to get home and me back here again in a few days. Thanks for the support folks. 🙂

I was wrong about manufacturer, it's a Valeo. The car has dealer-fitted detachable towbar and rear parking sensors, but I suspect the alternator was not changed from factory supplied one at the time. It's on the PR list as 110A. I will try searching 03F903023D - Bosch 140A instead, thanks @stigma

110Amp, 03F903023E is the genuine part number, to suit 2012 1.2 tsi Roomster. Think it's a Bosch. If anyone knows where I could buy something plug and play compatible within about 40 or so miles of Ely, Cambridgeshire, please let me know. 🙂

Pretty sure I fitted a new regulator/brushpack before I fitted this (genuine, 2nd hand) alternator only 16 months ago, so I think it must be one of the diodes in the alt that has failed. I'll try to test how much ac ripple voltage there is when it's running, tomorrow morning.

Thanks. Just checked and this one engages and turns rotor in the clockwise direction, as expected. If rotor is wedged it freewheels with anticlockwise turning of pulley, again as expected. Can't blame that I reckon.

Check fuse 11, and message me if that is OK. I can potentially lend you a known good driver's side motor (which is the master of both). If that fixes everything you could buy it from me.

That's cheered me up Gaz, appreciate the sentiment greatly. Hoping it'll turn out to be the pulley, which I have one of at home, I think. Offers of cars from various family members in the short term to get us where we may need to be. 🙂

The third character of the part number tends to be different on parts that have distinct LHD and RHD versions. Double-check for match of that third character.

Sadly not just battery failure. Either alt, or alt freewheel pulley freewheeling both ways (is that possible?). Can't check the pulley for a few hours, at a family birthday in a different car. Not finding a replacement alt showing as collectable at either GSF or ECP within at least 25 mile radius. ☹️

Looking that way. Just picked up a replacement battery only a few miles away. Fitting it shortly.

Front suspension change was unremarkable really, did take a few pics I think which I may add later. Unfortunately right now I'm en route to Roomster breakdown. Somewhere in Norfolk, following a what3words address. Fortunately I had just finished an oil change on my sister's car, and we are under an hour away. VCDS and a few tools on board, but I'm not wildly optimistic of an easy fix. Reportedly a succession of warning lights came on, followed immediately by major power loss and luckily a safe spot to pull over into. Allegedly not even turning over now. 🥲

What makes you think the wiring has been changed?

You may be able to do the nearside, but offside won't usually go low enough due to driveshaft bumping into stuff.

Trusting what ECP, Autodoc etc. suggest for compatibility is often a bad idea.

Sorry, I don't have any such capability. @Carlston may be the man to help with this.

Washer pump for front and rear screen is the same motor fed by opposite polarity current down the same pair of wires from the BCM. So the fault seems very likely to be on the input side.

Confirming 1K0 413 031 BL (dropped in Oct 2023) superseded by 1K0 413 031 EJ.

Need VIN to look up properly, if you won't look for the sticker. I'll message you so you can tell me the VIN privately.

Look for another sticker, lower down on original shocks. This isn't the part number you're looking for, there will be a sticker with a number ending 413 031 xx which will give you the correct suffix.

If it were mine, a VCDS scan would be the first thing I'd do. There may be fault codes in the engine ECU that would give clues. A CHPA-code engine, from the VIN, I see. Wonder if the cam adjusters are causing trouble?

You probably need a new o-ring.

I can't see it being wise to spend a load more cash on a walnut shell blast on a hunch from a garage who appear to apply a 'just change everything we can think of' approach to diagnostics. Does the coolant temperature gauge sit at 90 after a few minutes running?