F.A.Q. - Ventilation system does not always work

When the blower doesn't work at all or, for example, only at max then it's time for a fix! There are two possibilities why the blower won't work. The first possibility is that the connectors on the back of the blower switch have gone bad, I have had this problem and the solution was to remove the blower-switch (0,1,2,3,MAX). Disconnect it from the wires and clean all contacts you can find with contactspray. Sometimes somewhere a bypass has been made in the wares. My old 480 had such a bypass and I have heard from others that they had one too. The connections of this bypass may also need cleaning/renewal.

This was the simple part... Well, the following isn't as hard as it may look, you just need a steady hand for soldering.
For this solution you will be working on the VEM. If you really have no idea what the VEM is, here it is: the VEM is the Ventilation Electric Module. It is used to spread fresh air through the car.

To remove the VEM you need to remove the large cover of the dash. If you don't know how to do that see: FAQ - lights are dull and need replacement.
This is the bottom side of the VEM. In order to reach the circuit board inside you need to remove the six screws (arrowed at the picture). Make sure you don't loose them...
This is the VEM without the bottom cover, you can clearly see the entire circuit board and all connectors.
Here you see the entire circuit board removed from the VEM.

While you're at it, replace the small bulbs and clean the buttons. And if you really want to make it look as new, buy a new knob to put on the lever. These knobs always turn ugly because of the acids from your fingers.
When you carefully look at the solder-joint you can see that it has a bad connection. Resoldering is the best solution! Note that the bad solder-joint here is for the relais that operates the blower.
This is how it looks after having made a good connection again.
Time to rebuild your dash! Don't be afraid of all the wires , they won't hurt you (if you have disconnected the battery as you should...).

Just make sure you put everything back as it came out, and tighten the srews well enough. Otherwise you may end up with noisy squeechy plastics while driving.
And after some effort on a rainy day you should be able to use the blower again properly!

We hope this topic has been helpfull for you. Thanx to Ed Koedijk for sending the pictures.