About 6 months ago, my car (a Mark 6 Volkswagen Polo GTI+ - not the one in the picture) developed a lovely fault: the blowers stopped working. Not completely, but enough to annoy me. Off worked, and full power worked, but nothing in between. Temperature control was unaffected, as was AirCon, so in the lovely August heatwaves we get in Britain, I was able to survive long drives, switching as needed between being cold or being able to hear my podcasts.
It was a weird one, that I hoped would go away on its own. A few months went by, and it sadly didn't. British weather is such that after that heatwave, everything went back to being grey and dull, and so I didn't desperately need AirCon, and I don't do huge amounts of long-distance driving anyway, so it was never really a priority. I mentioned the issue in passing to a friend, who'd mentioned a mechanic friend of hers had seen similar issues on other cars, and claimed it could be a wiring loom issue - no thanks!
Fast forward a few months, and the opposite problem began: It's winter, and it's cold! After putting it off and putting it off, I finally decided to give in, and look into the problem some more.
#Culprit
Rather embarassingly, I'd never googled (well, not literally Google.com) the issue - I'd probably have to take it to a garage anyway. My dad however, suggested I do it anyway. If I'd done this 6 months ago, I could have had blowers which worked a lot sooner. As it turns out, this is a fairly common problem, with a fairly simple solution.
On my car (and probably most cars it seems), the blower power control tweaks the amount of power being sent to the fans. 0 is off, so no power at all, and 4 is full power, so the full circuit is sent (probably 12V). Everything in between however goes through the resistor to step down the power for each setting. If the resistor isn't working, then power won't flow for settings 1-3, which matched my symptoms exactly.
So, assuming that's the culprit, I just had to swap it out (well, find it first).
#Replacement
These resistors are clearly a relatively consumable part (my car is only ~5 years old), so car designers made mechanics lives much easier and placed them in a fairly easy to access location. Finding said location was a bit of a pain. Looking it up online, there were 2 main locations it could be: behind the glovebox, or above the passenger footwell. I couldn't find a video for my exact model, just different, older Polos. As most of the videos I found showed it behind the glovebox, I started there.
I had a 50:50 chance, and got it wrong.
After spending about half an hour trying to take the glovebox and surrounding trim off, I was eventually met by a giant lump of metal and no resistor. When that plan failed, I attempted to contort myself into the footwell (I'm not exactly small) to take a look.
The resistor assembly generally took 2 forms. It was either on a small rectangular tray, not much larger than the resistor itself, or a much larger black circle. Knowing that, it took less than 30 seconds to root around the footwell to find the resistor. It slid to the side, and then I could pull it out and disconnect the attaching wires.
With the part acquired, I could find a replacement. Whilst I've always found it odd how much they lean on this in their branding, eBay is a pretty good resource for car parts. A quick search of the part number (2Q0959263
) came up with tonnes of options. The replacement part cost me about £30, including delivery, and was here in just a couple days.
Replacing was exactly the same as getting the old part out, just in reverse. Plug it in, push it through the opening, and slide it to the side to lock it into place.
#Testing
With the resistor replaced, it was time to give it a test. Switch the dial to 0, and turn on the ignition. Then I flicked it to 1, and heard the fan kick in, nice and slow - excellent! Running through the rest of the settings all worked fine too.
Problem: Solved!
In my case, it was just the resistor, and I'm very glad I wasn't looking at a wiring loom issue. It's been a few weeks, and it's still working just fine.