Wish I knew more about car stuff

The fan in my VW UP currently only works on full speed (4) and not any lower setting. It is an annoyance but not the end of the world.

Since today is routine annual service I asked if they can have a look at it while they have my car. £60 investigation fee. I don’t think they charged before to have a look, but ok. For that, all they could tell me was they want another £60 to take my glovebox out and poke around behind it. I told them no, as best case I can only imagine them charging yet more for replacing something expensive. I like a working slower fan speed, but not that much on a car that isn’t worth a huge amount and if more faults start appearing regularly might be time to think about replacing.

What I should have done earlier is Google the problem. It looks like it is a common thing on VW cars with the culprit being a resistor pack with a thermal fuse on it. I haven’t tried to narrow it down further for my specific model yet, but now I’m wondering how hard it is to access it and have a look myself. At least, I’m confident in electrical/electronics even if I don’t have tools from my former job at my disposal any more. If needed I might be able to bribe someone I know who still works there.

The service rep on the phone mentioned testing a fan controller. I now get the impression that the fan controller is literally the mechanical switch on the dash and a resistor. I dunno, for some reason I thought they’d do something smarter than that like PWM control which is much more efficient, if also more expensive. I think I answered my own question there.

Trade off as ever is how much is it worth my time to try fixing this myself vs living with my fan only being off or on hurricane setting.

Almost certainly a resistor pack.
The Galaxy has many VW bits and they fail just like bits without the supposed “German superiority”

Thats what it looks like, a multi-plug connector, two screws and you are done.
Probably behind the glovebox.

A how to video

A place to buy a new part
There is also an autodoc phone app, plug in the registration number and find the part, order online and in just a few weeks it will turn up.
The number of weeks depends on how Pissy the French customs are being at present.


Could be £12 plus postage, depends on the car and the type of aircon fitted.


if the interior is constructed the same was as the Citigo, all the bits were really easy to get to. Glovebox isn’t hard to remove as the cabin filter is behind it and a serviceable part.

There are some parts that require more persuassion that others, but generally on this platform I’ve found it a very logical setup.

Think of it this way, if you take it apart and can’t get it together, then you’ve done at least half the job of the £60 charge, so they should charge £30 to put it back together :wink:

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Logical is one way of putting it.
My thoughts are, Cars are mass produced white goods snapped together in a matter of hours by people on minimum wage after a few hours training.
What you don’t do is say that to anybody that works in the trade, especially a relative that was going to help you to swap out a gearbox.

The resistor has failed as a complete open circuit, it gets bypassed for full speed.
Mine failed partially, only worked on three and four.

I’m amazed that in a modern car with at least two data networks controlling everything else with CANBUS a bit of 1930’s resistor technology is used to vary fan speed.

Well, if it saves 30p off the production cost I know why its there.

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Thanks both. I did some more googling after the original post and you pretty much confirmed what I was thinking. Assuming it is that resistor (specifically the thermal fuse on that pack) has gone, then replacing that part hopefully isn’t too big a pain. Is it a screwdriver job or do I need funky sockets and such? Will have a look in the car later and see what else I might need to do the job.

It does make me wonder what the garage did with the investigation fee if they didn’t even get as far as pulling off the glovebox. Laughing on the way to the bank? Can’t change the past now but I know better for next time.

Edit: looks like a T20 fits so I’m good to go when I have more time to dedicate to this. I also looked at the list of works done, it looks like my £60 went into doing a testing script of some sort.

£60 to plug in a code reader = ouch

Yeah, given this sounds like a common thing you’d have thought maybe they could have got a bit further in however much time that would have bought. Assuming you had the tools on hand and maybe some clue about doing it, how long would it take to get the glovebox out and poke around? Or am I expecting too much, and they have a troubleshooting process that assumes nothing so that practically any person that comes off the street could follow it. Again, what’s done is done.

it looks like it’ll just need some torx screws for some of the dash parts and the center console has to annoyingly come out. I’ve just checked on mine and the “normal” way to access this would be to remove the glovebox and get access, but the YouTube linked by @MrTFWitt is accurate for my model.

if you can get to Oxford, I am happy to do the needful.
Drop me a PM if you want me to take a look.

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If your starter motor gives up, here is a simple rebuild guide.
Requires only Basic tools and fire.

Safety Flip-Flops are recommended.

The fun continues. I’m supposed to go away for the weekend, but car now wont start. It kinda tried 1st time, but not having any more of it. Lights go dim and the clock has reset. Battery?

I have no spare anything so I’m about to pop out for a charger. At least it wasn’t next week as I’m due to get my 2nd vaccination dose and it is miles away.

Edit: Might not know much about cars but more comfortable about batteries. With car “off” battery was exactly on 12v. Turn on the fan which I haven’t fixed yet, it dropped to 11V. I bought a 6A charger as the 2nd cheapest in the store I could walk to. On inspection of the box it is a 4A charger. Assuming battery is 20Ah that’ll be somewhat over 5 hours for a mostly full charge? Should I risk trying it earlier? Don’t know if I should write the weekend off yet. (edit 3: don’t know where I got 20Ah from, another look hows 60Ah)

Edit 2: Wondering if my battery is on way out. Charger now says it is full and gone into top up mode. 90 minutes from flat to full? Had car for about 7 years, and a quick google suggests typical battery life may be shorter, according to people who want to sell you batteries anyway.

it does indeed sound very much like battery

Give these people a call

MDC in Oxford are excellent, they offer battery testing in Swindon (You do still live in Swindon ?)
I doubt they would need much persuasion to fit it for you if they can have the old one…

Amazon sell Pocket sized Li-Ion jump start packs that will give enough current to crank and start most cars, some will do 20 jump starts before needing to recharge.

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I’ll check out MDC on Tuesday assuming I get home. After the 90 minutes or so with the charger it was able to start, where I drove for another hour or so to my current location. I’ll probably go home either late Monday or early Tuesday, assuming car still starts. Did pack a DVM and charger+extension so I can tinker a bit if needed.

I did debate getting a battery pack of some sort, but if it is the battery on the way out then replacing the battery would fix it and I’d hopefully not need it again. Unless it is something handy to have “just in case”.

The charger pack is handy when somebody needs a jumpstart and you dont want to use your car to make it happen.

After seven years if this is the original battery with lockdown adding to the period of the battery not being charged I would expect it to be goosed.
You just need the cheapest path to resolution.
The booster pack will get you to somewhere for a new battery to be fitted.

There is a known shitty spot in VW electrics where the battery will not be charged but the charge warning light does not glow.

Check for a terminal box a bit like this under the bonnet, it takes the main feed from the alternator and shares it around.
If the charge feed is corroded (left most in this picture) no power heads towards the battery but everything else works fine.

Oh, that looks like the wiring pack on top of the battery, and possibly the biggest barrier to me replacing the battery myself as it didn’t look obvious how to get it out of the way.

I’m about to do a voltage check on the battery shortly which might give me some indication if I need to get the charger out, or I might be ok to get home tonight. Charging will be interesting since I’m parked on the street on the opposite side from where I’m located.

Worst case I can see if I can find a local car parts store that is open today I can get a similar battery booster pack from.

Edit: car started ok as I moved it closer to where I’m currently located!. Battery voltage under fan load was around 11.6v, so still of concern but not as low as when it wasn’t starting which was 11.0v. I should be good to hunt out a new battery tomorrow.


The battery should be close to 14v with the engine running.

If the inside of the junction box looks like that you found the cause of your woes, you will run out of electrickery without any warning lights if the terminals are corroded and have been heating up.

It is either German engineering that is faulty OR it is a deliberate degradation to make you think about a new car at about seven years.

If its a four door car you may be getting damp carpets, the door card seals degrade and let water into the floor pan and soak the carpets, there are electrics for the central locking under the passenger seat which get soaked at about seven years in.

The MIL has a Seat Ibiza that went a bit swampy, £3 of B&Q sticky backed draught excluder foam fixed the water ingress.

From memory it was around 14.5v with engine running, but that is more the output of the alternator and not an indicator of battery health isn’t it? Unless the battery is so dead it is pulling that down. For a big battery capacity I wouldn’t expect too much voltage drop with a load like the fan.

Haven’t tried to crack open that box yet. There’s a lot of clips, and my track record with clips is that if I get them off, they don’t often go back on again. I might give it another go later.

Anyway, I’m not home. Nothing to do with the car. Ended up going to a pub and found a rather nice whiskey cider. Still aim to get the battery checked out tomorrow, just maybe a little later in the day.

Pub sounds like the more rewarding option.

Happy to source and fit a battery if you like,
PM me the registration and I’ll pick one up from my local supplier if you are stuck.

Just got back from MDC, they couldn’t do the test as they only had one person in shop, so I will return tomorrow morning. I could have phoned ahead but they’re 10 mins from me anyway (or 15 if you’re me and miss a turning).

Some more info while at it. The people I was staying with have the same car, slightly younger. I took idle and fan load voltage readings on theirs. It was same as mine. So… I dunno any more. Well, it means one of two things: my battery is ok if their battery is ok. But given they have same car of similar age, their’s might not be far off going too.

I’ll let MDC do the test tomorrow and take it form there. They wanted £52 for a Lucas battery if needed, forgot to ask about fitting. I was sniffing around the Halfords/ATS websites, and they’re ball park double that.

While at it, here’s a photo of the wiring box, no corrosion visible to me, and fuses intact. No clips were harmed in the process.