Heater Control fix guide.

[Ferret]

Okay, so I got very rapidly fed up with having just slow or blow your head off fan speeds... so I decided to fix it and take photos along the way.

Apologies for the crappy phone camera!

This fix is for the rotory 1-2-3-4 type controls, not the climate control.

Furthermore it's a fix for the 1-2-3-4 becoming 1-1-1-4, not 4-4-4-4 if that makes sense! The latter of these two may be fixed by dropping a new resistor pack in at a cost of £19+tax from the dealer (See the rather excellent bmwe34 website.)

The core of the problem is the actual motor switch (props to Morgenster for pointing me in the right direction!) most people tend to leave their car on setting 2 or 3 permenantly, resulting in these burning out the quickest.

What you will need:
Full set of normal screwdrivers.
Small jewellers screwdriver.
Pair of good strength needle nose pliers.
Emery board/nail file if you've got one (Disclaimer: nick the wifes at your own peril!)

So, we begin:
You're going to need to pop out your heater control panel, to do this pop off the left hand sides screw cover plate and insert a small flat bladed screwdriver into the arrowed hole, push inwards firmly and the unit should kinda go *snap* and pop out a few milimeters. You can now use the same small screwdriver to carefully lever the unit out.


You'll have to learn how to wrestle all the connectors etc out the back - it's almost impossible to explain and

I'm too damn lazy. Just dont overstress anything or you'll be in trouble.


Once you've got the panel free, turn it around and get hold of a small long reach phillips screwdriver and remove the three screws which go into the holes arrowed here:

You'll have to carefully prise the potentiometer off the back of the switch as well... use a little flat bladed screwdriver to do it and it comes off quite easy.
Again apologies, most of these photos were taken as an afterthought after I figured out what I was doing.

...post to be continued...

[Ferret]

Once you've got the rotory switch out, it's time for a little violence!
The switch is practically a sealed unit, and I was looking how to take it apart while still being reliable after reconstruction... the short answer is that there's no real way to do it - if you force the case open it'll never go back together properly again.

Solution! You'll notice on once side there's an aperature with 'bars' across it - take your needle nose pliers and snap off the bars - which should leave you with this:


You can now see inside and see four terminals that come down and four mobile pads that move up to touch the terminals. Get your emery board (I used a small jewellers screwdriver to scrape crap off the pads) and clean up all the pads. Once cleaned, plug only the switch back into it's appropriate connector - set the cars ignition to the run position and check for function. The blower should now work properly in all positions regardless of the fact that the rest of the controls are not plugged in.


At this point you can just reassemble the whole thing if you like, but I started with a little bit of a clean... which could have been a bit of a mistake.
Popped off the sensor duct to find this **** everywhere, 10 years of dead human by the look of it:


Make sure you get well clear of the car before you blow this crap out - there's usually a lot of it in there.

BE WARNED! If you disturb any of the **** off the temperature fan (marked 2 above,) it WILL start squealing annoyingly. Usually just as you've reassembled everything and thinking 'well that was eas... *squeal*' and no ammount of hammering the dash will stop it doing it.

[Ferret]

If this happens to you, here's how to fix it:
In the above photo disconnect the connector marked '3', then pull the screws arrowed below:


Pop the back off the annoying fan, then turn it over:



Take your needle nose pliers and put the tips where the arrows point in the final photo above - squeeze very gently until the metal plate bends upwards /very/ slightly. All you're trying to do here is move where the motor shaft sits by a few microns - enough to get it out of the grooves causing it to squeal.

Plug everything back in without reassembly first to make sure there's no annoying noises, if there are readjust with another tiny squeeze on the bearing bottom plate - otherwise reassembly is the reverse of disassembly etc etc ( you guys know the drill ) and you should have a completely working heater system again.

Finally - I made the mistake of fitting a new resistor pack first, which isnt the problem. Ergo my old one's free to a good home in the UK for anyone that needs it. Beer tokens are accepted as postage!

[Sidney Rough-Diamond]

Opps , what twat suggested it was 'only' the resistor pack
I look forward to reading about how to fix BMW head units that make odd noises next.

[Ferret]

Opps , what twat suggested it was 'only' the resistor pack
I look forward to reading about how to fix BMW head units that make odd noises next.

Heh, the head unit's on my hit list

To be honest I should have checked the resistor pack first - it's me that's the twat for not doing that lol.

Managed to sort out the minor rattle/tick on the right bank! Two of the spark plugs had managed to back themselves out!? I dont know how either because the threads in the head are still in good condition.

[filmy540i/6]

Heh, the head unit's on my hit list

To be honest I should have checked the resistor pack first - it's me that's the twat for not doing that lol.

Managed to sort out the minor rattle/tick on the right bank! Two of the spark plugs had managed to back themselves out!? I dont know how either because the threads in the head are still in good condition.

Another awesome write-up, and another reason the internet is the best thing since ZZ Top videos for car guys.

But let me ask you: when you pulled the heater control panel, was there a light source in there? A bulb (or two) that are supposed to be plugged into it? Mine doesn't light up at night and I think it's supposed to do so.

Thanks again for taking the time to help others.

- Gary

[Ferret]

Another awesome write-up, and another reason the internet is the best thing since ZZ Top videos for car guys.

But let me ask you: when you pulled the heater control panel, was there a light source in there? A bulb (or two) that are supposed to be plugged into it? Mine doesn't light up at night and I think it's supposed to do so.

Thanks again for taking the time to help others.

- Gary

Yeah all the heater controls should light up at night (I think, someone correct me if I'm wrong,) that's next on my hit list as the rotory heater controls dont illuminate on mine!

Will write that up as I do eeet!

[DaveVoorhis]

Yeah all the heater controls should light up at night (I think, someone correct me if I'm wrong,)

Yup, they should. Mine get religion once every thousand road bumps or so, and then for about a mile of smooth road they're enlightened until another bump puts them in the dark again.

[NielsGalan]

Good writeup, thanks.

I've been the last couple of years in Blower on 1 1/2 land. I thought it was a bigger deal to fix. Been reading up and down about resistor packs, swords and other fun stuff. All it took was a bit of sandpaper (and having to remove OBC, Stereo etc to get the god damn piece of **** together again - only to discover that the lights in the stupid thing have ceased working ...)

Thanks again.

[Ferret]

Thread revival post