This was our experience after buying a 1998 VW Passat, cheap. After doing some research we realized that the wires in the Comfort Control Module might be corroded, leading to electrical problems. Our windows didn't work and neither did some interior lights or the power locks, but our sunroof and other interior lights worked just fine.

Whoever decided to put a major electrical module under the feet of the driver where water might (will!) get to it...well, they weren't walking on the bright side of the road that day. And VW not changing it in the 7 years they made this model of Passat?! Thus you have a very common problem. This is a good how-to on cleaning the drain holes that could be causing water to hit the CCM, so if you do find corrosion make sure to clean the holes as well.

There is another website that has a "how to" for this issue with photos on headfuzz. When we tried to find this website before it was down, so that's why we decided to take lots of photos when we repaired our Passat. After reading this and seeing how doable the repair is, I hope you might be encouraged to fix your own lovable lemon!

These are the things you might need for your CCM repair: pliers, screwdriver, electrical tape, butt connectors and a sharp knife.

The first thing to do is take the plastic footguard off with your screwdriver. 

Next you need to pop off the long plastic piece that goes between the metal frame and the footwell fabric.

Lifting the fabric up you will see a bundle of wires attached to a black box. The fabric may be a little hard to lift but it's doable. To make it easier to pull up you can flip off the clips that hold it down.  Reaching in, grab the black box out and place it on top of the fabric.

The snaps may be tight on yours, we had to use the screwdriver to pop ours open.  Once you've gotten the box open, take a close look at the wires.

As you can see, once unwrapped there was clearly a problem with the black wires. This is actually one black wire that is connected to four other wires.

If you don't see any problems at all with your wires then you have two options.  One:  disconnect the wires (harness) from the computer box and check each one with a multimeter.  Two:  open the computer box (printed circuit board or PCB) and look at it to see if it is corroded or burnt out.  If it is, then you'll probably need to replace the board itself.

Take the corroded wire ends and using your sharp blade, cut around the wire about a 1/2" away from the end. Peel the 1/2" of plastic off. You should now have clean wires at the tip, if they are not clean you can use a little reflux to take off the corrosion. Make sure all wire ends on the affected circuit have visible metal ends.

Take a connector butt and put it on one side of the circuit.  In this picture, all four black wires are in the connector already.

Place the other wire end into the connector.  Hold it together carefully and get the pliers.

Place the pliers on the middle of the connector.  Squeeze tightly on the pliers; what you are doing in essence is binding the wires on each side together in a metal envelope that is covered in plastic.

When you are done squeezing, the connector should look like this. The wires on either end should be firmly connected.  If wires do come out, then you have to do it over again (with a new connector or with the same one after you've unbent the metal inside).

Now you can put the keys in the ignition and try using what wasn't working before. For us, it was the windows. They work! Yay!

Make sure you inspect all of the wires in the CCM and repair any that need it. If the wires are not badly damaged, a little electrical tape around the connection may be all that's necessary.

Once you've repaired all the wires, close the box and replace it under the footwell fabric. Close up the gap between the frame and fabric with the plastic cover again and replace the footguard. There! You're done!

As you can see, although this is an electrical repair, it is easily within the grasp of anyone.  Don't be afraid to try!  You'll feel like you have a new car!