Blower fan does not work now in my 1981 T25

[Ant-t]

Excellent video CovKid, thanks very much, a great mod!

[crazymilk]

Time to update this one I think, with respect to a more modern way of controlling the blower - ie dumping the dinosaur resistors and high-speed relay altogether and using a dedicated motor speed controller instead. Both Ghost and I have mentioned this a few times in recent months, and I've been asked to explain in more detail how to wire it up, so I think a video demo is finally in order. Since this is a project that several seem interested in, I'll put it in the WIKI too.

So why change to a dedicated controller? Well, apart from it being more efficient and more controllable, its actually cheaper than, or no more than replacing damaged resistors and if you're planning on replacing the fan, thats an ideal time to consider upgrading the control circuit too. On a stock system that is working fine, its best to leave things as they are unless you're pedantic. That said, resistors get hot (and can melt nearby plastics) and it wastes a lot of power.

This evening I wired the new controller to a brand new blower motor on my bench and I was really impressed! Boy does it go. Unfortunately I don't have the lights needed to video indoors this evening but I'll do that tomorrow, including how to determine the correct polarity for a new blower motor which isn't that apparent.



Conclusion? Really nice - total, smooth control of motor from virtually nothing, to flat out.

Personally, I think this beats using the 'notchy' stock resistors that set blower speed, particularly when you consider its around half the price of new resistors and gives infinite control. My controller has a click-off function on the control knob (pot) and this is confirmed by an LED on the edge of the circuit board. I'm inclined to extend that LED so it can be seen on the fan control facia or alter the stock wiring so the blower is ignition dependent. The existing fan switch will be gutted out and the new knob fitted in the same place.

Its important that you get one with the control knob on flyleads as that makes it so much easier to fit, but otherwise its a doddle

There are a few around with displays but can't see any point in that - its just a blower after all. I'll say one thing though, that blower motor puts out way more air than any 240v desk fan I've ever bought. Heres a simple explanation of PWM and why you might want it: https://www.youtube.com/watch?v=Lf7JJAAZxEU" onclick="window.open(this.href);return false;

Sorry to raise this old thread but could somebody point me in the right direct to get something available in the UK that I can use for this fan mod?
Thanks

[Oldiebut goodie]

http://www.ebay.co.uk/itm/sourcingmap-9 ... SwWxNYqyZP

[irishkeet]

http://www.ebay.co.uk/itm/sourcingmap-9 ... SwWxNYqyZP

Great thread, dont know how I missed it before. Just got the foam kit from bricky and just ordered this so while its all out ill have a play with replacing the controller Many Thanks

[CovKid]

https://club8090.co.uk/wiki/VW ... rade_(PWM)

As you can see, I modified facia plate but since these PWM control knobs vary somewhat, you'll need to decide the most logical way to fit control knob.

I've lost track of the projects and mods I've posted in threads and the WIKI but this was the most satisfying one by far. Its just better than what VW fitted and easy in terms of servicing as you can swap the controller out without having to split the blower box or remove dash.

I'm presently working on a new one for the Summer on building an interior from scratch with limited woodworking skills - no chipboard or MDF either Best place for that stuff is on the bonfire.

[al*mk1]

Awesome Wiki, CovKid.

My blower is not working at the moment.
I have an old switch and maybe even a spare motor from my Mk1 Golf so could potentially make do, though this is a very appealing mod!