Window switch electrical contacts on 1999 ML320 - HELP!

I have an ML320 1999 and the driver side window switch is bad. The window switch controls the downward motion but when I lift up on the switch nothing
happens (not even any light dimming). If I depress the switch again (with the window in the open position) there is a dimming of the lights so I know there is power to the switch and window. It appears the switch contact(s) to allow the window to go back up are bad.
We just got 18 inches of snow here in New England and this causes a bit of a problem!
I took out the console box and disconected the electrical wiring plug for the window sitches on the driver side. There are 7 wires into this plug. If I can figure out which one, or two or three, go to the driver window I can try and short these together so as to make the window go back up - then I can take the car in for repairs. I can't determine which wires to use though. I've been tryting to short out two wires but nothing happens which leads me to believe I probably need to work with three wires.
Any ideas on which wires/contacts in the plug I could short or contact together to get the window back up? The wire harness/plug seems to supply power and control both front/back driver side windows as well as the master lock/unlock switch. There are two white wires in the harness of 7 total.
Thanks. Walter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

You are right, this is a common fault with the ML

You need a new switch pack, and it sounds like you have already pretty much stripped it out, can you not just buy the part and then fit it at home?
If not then you can email me your chassis number and I'll have a look at the appropriate wiring diagram for you....
--

Lettuce spray for whirled peas...

Reply to usenet[at]miknik[dot]co[dot]uk
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is a very common problem on pre-2002 ML's. The only permanent solution is to replace the switch assembly. If you are out of warranty, you might still get it replaced by MBZ if you use the phrase "goodwill". Of course if you're under warranty, they will replace it for free. In fact, Roadside Assistance used to carry spares. If you want to DIY, then I suggest just buying the part. It's a 30 minute job at best and the part is very inexpensive (I've heard it's about $40 for the whole unit). In the mean time, if you can't make it to the dealer, look here for detailed instructions on how to repair the contacts yourself:
http://www.grill.org/rodney/mclass/mlswitch/index.html
--

- RODNEY



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Excellent guide to the removal and repair of the switches.
This was my experience in my 2000 ML320. At the time, my car was about 2 years new. I'm with my wife and sleeping 2 year old daughter at about 7pm on a Sunday night, leaving Lake Tahoe via I-80 west from Truckee heading home to Marin. It's 17 F outside. I had noticed the increasingly more frequent intermittent power window spasms and said to myself, I should try not to use the window and open the door instead. If you don't know that route, there is an agricultural check station on 80 at Donner Lake. I pull up and absenmtmindedly put the windiw down to tell the attendant that I don't have any produce from out of state.. Now the window isn't going up, no chance. Thoughts of turning back and worrying about it the next day seemed appelaing but it was just as cold back there and about 15 miles back to the condo and I had to work the next day. I thought of how I might safely cover the window to make the 3 1/2 hour trip. The whole time thinking about my sound asleep daughter. I pull over and call Mercedes roadside assistance. The rep tells me the nearest service center is 100 miles away, and he would have to call a technician to meet me there. I was impressed by the offer but that wasn't the solution. I explain my situation and the tech on the phone says he isn't supposed to tell how to do this but the solution was to break the switch by pulling up hard on the lever. Hard enough to pull it off completely, once off, the switch body can be removed and you can see inside and look at the copper contacts. There are 3 of them, he tells me to press on the middle contact with a pen or toothpick or something like that. I use my ever present ball point pen and up goes the window. We're back on the road in less than 10 minutes. The next day I call service at the dealer, make an appt. to bring it in, they give me a new E-class to drive for the day and it's fixed. I've had no problem with it since. My point is, the switch may been a bad design but the service makes up for the occassional imperfections. A note on the remedy, they replaced the window switches with the ones they use in all of their other cars with the '02 model year.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have heard others mention this "emergency fix". I tried this on mine and ended up causing the entire switch assembly to break away from its mount and fall down inside the console. When I called for service, I was told the switches were backordered, and this was why I tore into them myself.

I wish that I could say the same. I have received nothing but horrible service from my dealer, and since there's only one in town, it's not going to get any better.

Yes, I believe the contacts are the same, but I do not like the location of the switches in any of the new models. I prefer the center console mounting of the pre-2002 ML and the older cars. Starting in 2002, they moved the ML's switches to be on either side of the shifter to make room for a cupholder. In the C and E cars, the switches are mounted very inconveniently on the lower part of the driver's door. The good thing is that they are auto-up/auto-down on all windows now.
--

- RODNEY



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Here is what I found to solve your problem..I solved mine http://www.grill.org/rodney/mclass/mlswitch/index.html

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Keep in mind that this fix is only temporary. The contacts will most likely become misaligned again. The real solution is to get a new window switch assembly from the dealer that has redesigned contacts. If your truck is recently beyond the warranty, you might try getting them to replace it as "goodwill". If you have to purchase a new switch assembly, I believe the cost is less than $50. Using the directions noted above, replacing the broken assembly with a new one is very easy. One thing I'll note about the directions is the single wire connector may not exist on earlier models (pre-2000). That wire allows user programming of the auto-lock feature. Earlier ML's did not have this capability and thus do not have the wire (only the dealer can program the auto-lock on those).
--

- RODNEY



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.