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Discussion Starter · #1 · (Edited)
Window Switches-Repair and Modify Part1

Post 1 of 2 long posts

V.W switches installed in the door panels can be unreliable.:( Window functions can also be controlled remotely by software e.g. during roof operation or if the RLS detects rain and open windows. The following lists the type of faults attributable to a manual switch:

1. A switch will close a window but not open it.
2. A switch will open a window but not close it.
3. A switch will start to control a window but hesitates or stops.
4. If a switch has ''1 touch' function, it only works with finger holding switch.
5. Individual switches work but the 'All Windows' switch does nothing.
6. The 'All Windows' switch works, but some individual switches don't
7. When lights are on a switch legend is not lit.
8. A switch rocker sticks and stays down or up (easy mechanical issue?).
9. The fuel flap switch doesn't work.
10. The trunk release switch doesn't work, but the trunk opens on the emblem, remote or roof op.

Most switch faults can be confirmed by operating the roof. If all windows go down and come up, the fault is not control electronics but manual door switches.

These V.W switches have a reputation for failing but EOS owners will have most failures - Why? The driver door switch panel molding is designed for fingers. Unfortunately, the shape in front of each switch acts like a funnel for any water and V.W switches are not sealed. EOS owners have a particular problem because there are no roof gutters and when a door is opened in rain, water spills off the roof on to the switch panel. The driver side panel is the most vulnerable to switch damage and faults

Many just replace switches, but in the EOS cabriolet the design problem remains and switches are still going to fail! There are plenty of Chinese copies but if you look at the attached switch table, no two switches work the same. These switches are very clever. Only one wire and ground is required to define up to 4 functions, how is this done? The switches can have a single on/off function e.g. the fuel flap and trunk release, single up or down op. for a window - the driver rear window switch, or window up/down with 1 touch in the switch fully up or fully down position.

These switches contain a circuit board with a simple chip resistor matrix. When a switch is operated, a single pin in the connector presents a resistance to the control module which derives an analogue voltage. By using different resistor values, the resistance on 1 wire tells the controller what window operation is required.

I show photos of water damage in MY07 drivers side front and rear window switches. The rear window fault is serious because it explained why I thought I had closed the rear windows when one was left open overnight! That switch only worked intermittently in the down position.

Repairing these switches better than before needs micro electronics or watchmaker type skills and a large illuminated magnifier. There are a couple of YouTube videos for V.W switches, but mine were not the same. A step by step tear down and fix follows for the V.W helag brand switches NOT Bitron (Italy). The Bitron switches were not used in the horizontal drivers side panel (pity) and those I checked were clean without water damage. Your switches may not be like MY07 or even improved, but I doubt they will be IP rated for water and dust.

1. You don't need to remove the door card to repair the drivers panel switches, or the passenger window single switch. On the driver side the trim molding around the switches can be lifted vertically to allow the switch panel complete with all switches to be removed. The passenger side requires the handle trim to be removed to expose 2 Torx fasteners to remove the handle. There is just enough room to release the connector and switch without dropping anything inside!

2. Mark each switch connector on the loom and switch body with white marker dots, it makes putting them back a lot faster. Disconnect all plugs and remove the driver side panel complete.

3. Start on the first switch for rear windows. Using 1 or 2 electrical screwdrivers, squeeze open the shell to allow the switch body to release and pull rearwards from the trim panel. Mark the base of the switch and one side of its shell for re-assembly.

4. Using 2 screwdrivers, carefully work each side of the rear switch cover (with connector) until it releases. Take care because small parts underneath may lift out, although there is nothing spring loaded to jump out.

5. You should have exposed the double sided circuit board and will immediately see the effect of any water damage. Usually this damage will be to the gold tracks, but can include through plated hole connections. Using a multimeter you can check for open tracks and plated holes which will probably be in areas that are no longer shiny gold. Clean the switch board, spring contacts and case with alcohol first. Do NOT bend or distort the spring contact fingers!

6. Now remove the small board from the connector shell. V.W use (at least 2) different types of switch. On Helag switches the board is held on 4 ABS black pillars with each end heat rolled to form a plastic rivet. Using a small bit soldering iron at 300 deg. C, carefully melt and work the edges of the plastic rivets towards the center to clear the board holes. Then carefully prise up from the corners and sides until the board lifts away.

7. To repair tracks and plated through holes you can use fine copper wire. Even if part of the track is missing, you can still solder links between surface mount components. Some plated holes are attached to the switch contact pads but set back from the actual spring contact area. You can solder a link wire through the plated hole. but do not flow solder over the contact area. Afterwards carefully file across this solder joint to reduce its height.

8. The next stage is weatherproofing the board: Using masking tape, cut small pads with a scalpel and cover the leds on the visible side, the 'forked' contact areas, including small circular pads used for 1 touch contact. Wrap masking tape around the 4 contact pins. Using clear coat lacquer, spray 2 coats on each side of the board. It dries fairly quickly, but 10 mins at 60C in an oven helps harden it.

9. Carefully lift away the masking pads and check there has been no lacquer creep into the contact areas. Clean them with a Q tip and alcohol before reassembly.

10. Replace the board on the 4 pillars ensuring it is pressed right down and level. Work the soldering iron over the plastic to melt and reform the hold down rivets. You can use black Tywrap as additional filler. Hot melt glue doesn't work!

11. Reassemble the base and click back into position, making sure that all 4 tabs are located and the bottom cover sits flush.

12. Test your switch with an ohm meter. Pin 1 is common and the switch functions (resistance) will be on pins 3 or 4. If your switch has 1 touch function (2 clicks up or down) you need to check all 4 functions. You should also connect +12V to pin 2 and 0V to pin 1 to check the led works. Fit the switch in the switch carrier then test in the car, move on to the other switches and repeat.

13. I struggled to remove the 'All Windows' switch body from its surround. On that switch I was able to remove the base to access the board.
 

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Discussion Starter · #2 ·
Window Switches - Repair and Modify. part2

Part 2 of 2 long posts

MY07 used the following switches from 2 manufacturers yours may be different (or better!)? Helag seem the worst for water penetration.

1. Drivers rear window, Blue base,V.W Germany, Helag HLN, 100-959-858A
2. Drivers front window switch, black base, Helag 04 DL3006
3. Drivers All Windows switch, black base, Helag 1Q0 959 873B

4. Fuel flap & Trunk release blue body brown case, BITRON (Italy), 3C0959903B.
5. Passenger left side single window switch, BITRON (Italy) 1F0 959 855

The V.W Helag switches offer no protection against water ingress - holes everywhere and their boards are not lacquered. BITRON (Italy) switches are a better design because they use a silicone rubber moulding fitted over the circuit board and switches. It could have been more water resistant if they had not left the molding open for the led or used a clear window? I will research whether BITRON (Italy) make all the EOS switches. I am also getting some Chinese switches to open and play with.

You have inspected all your switches and fixed their faults but the problem still remains that you open the (drivers) door and water pours into the switches. I can't re-design the V.W switch molding but I have added a flap across the driver and passenger switches. It was the best compromise without ruining the aesthetics too much.

I shaped a clear melamine laser transparency sheet which is held along one side by the trim panel. Warming the sheet at 170 deg. C I got it to lay flat across the switches. Then I added a small 'pad' of clear double sided sellotape. The cover flap stops water getting into the switches!

Sorry I haven't embedded photo links in my text, but you should be able to work them out.
 

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I believe the facelift Eos has Bitron switches all round: when I got my set of chrome switches that came from a facelift Eos and the all-windows switch had the membrane as shown in your photo.
 

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Discussion Starter · #4 ·
That's useful info because if so I can compare my part numbers with the later model? You say they are chrome finish? Is that all over or just the raised 'bar' across the front? I would need to see how they would match aesthetically - can you post a photo? Cost might be an issue if they have to come from the Stealer as OE parts. I've got some Chinese switches coming to see what they are like inside. The Bitron switches seem a better design and should last longer, but the problem of stopping water getting on them still remains.
 

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Discussion Starter · #6 ·
Thanks. I can tell you how the 1 touch works on these older switches which you can work out from the photos. MY07 has 1 touch for the front windows but not the rear. That may be due to safety concerns, because from the driver console you can't see if little Johny or your pooch has hands or head out of a rear window?

The 1 touch and non 1 touch are mechanically the same switch except on the outside under and over the rocker there are a line of peg stops. The 2 end stops if present stop the switch lever going full up or full down into the 1 touch positions. The switch sprung levers have a second contact in the center of the spring which only closes on a contact pad in these 2 positions.

I did think afterwards of swapping the switches over to see if the controller could give 1 touch for the rear because both switches have the same resistors? But everything was back together and too late to try. If that works then it's only a case of snipping off the outside pegs. But I think V.W had the correct safety concerns not to enable it for the rear windows?
 

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I don't know, but I do know that the facelift all-windows switch has one-touch operation which does not work on my pre-facelift Eos.
 

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Discussion Starter · #8 ·
MY07 is the same but I can tell my switch and others don't use the extra contact because there is no double switch feel when you take the rocker fully up or down - it has the two limit pegs I mentioned earlier. But if your Facelift all windows switch has those 2 click positions (confirm) and 1 touch doesn't work, either the resistor value in the later switch isn't what the earlier controller expects or the earlier controller firmware isn't programmed to accept the 1 touch resistor of any value. The way to check is to try a variable resistor across pins 1 & 3 or 4 from zero ohms to 1K and see if you get 1 touch. If the controller accepts a resistance value different to the facelift switch, you can open it up and change the chip resistor value.

The interesting thing about these window switch functions is they can't be easily changed using diagnostics.

1 touch does work for all windows via Canbus control, because that's what the roof op. and RLS does. I am hoping to look inside some Chinese clones and don't mind buying one sample to test, but the problem comes guaranteeing the other switches I might buy from China are from the same manufacturer and design. One Fleabay seller is offering the Facelift switches as 'improved'. Their part number is the same as the list you posted but starts with '5' which may be their way of saying this isn't a copy breaching a V.W license?
 

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MY07 is the same but I can tell my switch and others don't use the extra contact because there is no double switch feel when you take the rocker fully up or down - it has the two limit pegs I mentioned earlier. But if your Facelift all windows switch has those 2 click positions (confirm) and 1 touch doesn't work, either the resistor value in the later switch isn't what the earlier controller expects or the earlier controller firmware isn't programmed to accept the 1 touch resistor of any value. The way to check is to try a variable resistor across pins 1 & 3 or 4 from zero ohms to 1K and see if you get 1 touch. If the controller accepts a resistance value different to the facelift switch, you can open it up and change the chip resistor value.
IIRC the all windows switch sent the signal for up on one pin and the signal for down on another, so it's different even to the regular window switches.

The part numbers, while unusual, are real.
 

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Discussion Starter · #10 ·
... All the switches work the same way by presenting a resistance (including zero ohm) to the controller. The only difference with the All Windows switch is They don't use a resistor and the switch simply closes to pin 1 ground from pins 3&4. The controller just needs to see a pull down to zero volts from either pin 3 or pin 4. I didn't measure it but I suspect the source resistor in the controller is about 1K ohm.

It's interesting that many have viewed the photos and description, but few have viewed the text file which is the Switch table explaining what each switch does and what resistance is produced.:confused: If you get a clone switch or a switch from another VAG that looks the same, there is no guarantee it will work in an EOS unless the resistor values are similar to those in my table.

I came across this analogue signalling technique on Apple mains chargers to distinguish between fast and slow chargers. Many buy clone chargers and cables for idevices and find they take longer to charge up. Apple are very crafty because they use a special non-standard resistor in their fast chargers to set a voltage on the USB data line which is read when you connect any usb charger. But with a variable resistor you can get around that and save money. :)
 

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It's interesting that many have viewed the photos and description, but few have viewed the text file which is the Switch table explaining what each switch does and what resistance is produced.:confused:
TBH I didn't open it because I didn't see it there!

I can't remember the resistances on the facelift all-windows switch but I think they're the same as the front window switch in your list.

The other facelift chrome switches I got were slot-in replacements - but I did buy them embedded in an armrest, so they're originals.
 

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Discussion Starter · #12 ·
Until somebody plays with a variable resistor we do not know what tolerance range for resistor values may be accepted by the controller used in early and Facelift models. I measured my values for 'early', but the resistance value range needed for a function to work could be wider?

I see some Fleabay sellers selling all the switches assembled in a tray but the All windows switch looked different? Does the facelift EOS use this different tray and is it a drop in replacement? They also include the headlight switch in the chrome set, but I still wouldn't risk buying a Chinese set unless I could look inside a switch. :(
 

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Until somebody plays with a variable resistor we do not know what tolerance range for resistor values may be accepted by the controller used in early and Facelift models. I measured my values for 'early', but the resistance value range needed for a function to work could be wider?
True enough. I solved my problem but we don't know exactly why it works - just that it does ;)

I see some Fleabay sellers selling all the switches assembled in a tray but the All windows switch looked different? Does the facelift EOS use this different tray and is it a drop in replacement? They also include the headlight switch in the chrome set, but I still wouldn't risk buying a Chinese set unless I could look inside a switch. :(
This is an example of people listing stuff for the Eos because it works for the Golf. The facelift Eos switches are identical in layout to the pre-facelift version. If you see switches assembled in a tray then it's definitely wrong - at least that was my experience when I was on the hunt for chrome switches. They may have made other stuff since then - if you provide a link to the listing I can tell you for sure :)
 

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This is a great thread explaining the window operation switches and their fallibility.

My 2007 EOS 2.0 has a weird problem. The roof operates properly and commands all four windows to go down (but the left rear window only goes down half-way). So I manually lower that LR window and the roof continues its proper operation.

If I use the "master" all-window switch, yes, all four windows go up and down.
But, the right front passenger switch does nothing and the driver's side switch for the front passenger window does nothing. Are BOTH switches non-operational?
I can't seem to find links to instructions/videos on replacing the switche(s)
 

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Discussion Starter · #15 ·
I can't seem to find links to instructions/videos on replacing the switche(s)
The switch assembly lifts out with a plastic pry tool. I'm pretty sure you may have to remove the door card because the connecting wires inside are short, but I can't remember now?
They fail because water from the roof falls on them when you open the door in wet weather!
 
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