1990 R129 Window not working.

[roblloyd]

Have a 1990 R129 mercedes and the driver window is stuck down.
Have had problems with this window for years. Some times it kust goes off and a bang on the door brongs it back on. BUT know its stuck down and needs a m o t today.
Not took the hard top off for this year so will try that today.
Got this code 12- 5 , left front door actuator , open Circuit?
Any advise?
Rob

 

[mioba]

yes replace the left front door actuator. but since it works after a smack it could be loose, dirty, getting it in your hand will tell you.

 

[roblloyd]

Bought another door and lucky its the driver side door.
BUT can you tell me were on the door is the actuator is?
Thanks
Rob

 

[roblloyd]

yes replace the left front door actuator. but since it works after a smack it could be loose, dirty, getting it in your hand will tell you.

Were is the actuator on the door?
Thanks
Rob

 

[LostKiwi]

A 1990 car has only two components in the door.
1. A switch in the bottom of the door that acts as a limit switch.
2. A motor and associated hardware to lift the glass.

If it stays down it may be the mechanism jams or the motor has a dead spot.

It may also be a bad connection, bad wiring or bad earth.

 

[roblloyd]

A 1990 car has only two components in the door.
1. A switch in the bottom of the door that acts as a limit switch.
2. A motor and associated hardware to lift the glass.

If it stays down it may be the mechanism jams or the motor has a dead spot.

It may also be a bad connection, bad wiring or bad earth.

Lostkiwi
Was moping you would come on here.
What do you think about the actuator? Would that have any problem with the window going up and the fault code in #1?.
Had this car for 13 years and the window works fine 95% of the time but now its stuck down and will not come up. Think i know what started it , some one used the cigarette lighter and some how the window would not come up after that.
If its a bad earth were would that be and could i find it with a code reader that i bought from Malcolm (God rest his sole). Best £15 i ever spent.
Got another door for parts i bought 10 years ago complete for £50.
Hope you can help
Thanks
Rob

 

[LostKiwi]

Which module is reporting that code and how many flashes?

 

[roblloyd]

Which module is reporting that code and how many flashes?

So it number 12 with 5 flashs on the 16 point code reader socket.
12 - 5 = Left front door actuator , open Circuit.
Any clues?
Must be something simple because its been happening for years bit never had the window stay down.
Rob

 

[LostKiwi]

Don't know where you got your description.
My data says Pin 12 is IRCL.
5 flashes = Infrared remote control receiver, Left front door/Right front door/Trunk lid Green
indicator lamps, short to ground

Nothing to do with windows.
As I said the windows on these are pretty basic.
The control is handled by the RST (roadster soft top) module under the rear seat.
In the door the only electrical components are the motor and the limit switch in the bottom of the door.
Check earths and power using a multimeter and rest bulb. Check for a jammed mechanism preventing the motor working.

 

[roblloyd]

Don't know where you got your description.
My data says Pin 12 is IRCL.
5 flashes = Infrared remote control receiver, Left front door/Right front door/Trunk lid Green
indicator lamps, short to ground

Nothing to do with windows.
As I said the windows on these are pretty basic.
The control is handled by the RST (roadster soft top) module under the rear seat.
In the door the only electrical components are the motor and the limit switch in the bottom of the door.
Check earths and power using a multimeter and rest bulb. Check for a jammed mechanism preventing the motor working. View attachment 79663

Must have got mixed up with the wrong page.
Thanks for letting me know.
The moter must be 3 bolts ? With the multimeter what setting do i need to have it on?
Sorry for all the ?s but only know very little about cars.
Rob

 

[LostKiwi]

Does the window go up if you raise the roof?

 

[roblloyd]

Does the window go up if you raise the roof?

The hardtop is on and will not work since the window got stuck. Was ok before. Going to take the hard top off manually tomorrow and see how that goes BUT i know its a silly wire problem some where. Will also do another code reader and see what comes up.
Will let you know how i get on tòmorrow.
Need to get that window up some how tòmorrow.
Rob

 

[LostKiwi]

The motor has two wires. I suspect one will be +12v for up the other for down with earth through the chassis. Can't guarantee that as I haven't had issues in that area. You could try putting a multimeter set to voltage on one wire and earth, operate the switch and see if you get reading. Then try the other wire. If nothing put the meter on both wires and try it. If still nothing you have either a broken wire or bad switch.

 

[roblloyd]

The motor has two wires. I suspect one will be +12v for up the other for down with earth through the chassis. Can't guarantee that as I haven't had issues in that area. You could try putting a multimeter set to voltage on one wire and earth, operate the switch and see if you get reading. Then try the other wire. If nothing put the meter on both wires and try it. If still nothing you have either a broken wire or bad switch.

Ok. Got the hard top off manually and also put the sort top up the same way But no joy with the window its still in the bottom of the door.
Found the 2 wires for the moter and undid them and then took the moter out by un doing 3 nuts. Was surprised how easy it came out with the window down. There was a bit of crap grease all around the moter so gave it agood clean. Put the 2 wire back on door , they go to a plastic part thats clipped into the door with another 2 wire.
The motor starts working. Put it back on with the window at the top now and the sort top worked on the button BUT after 2 goes at this the window get stuck at the bottem again.
Because i never used the switch i am thinking its

 

[roblloyd]

Ok. Got the hard top off manually and also put the sort top up the same way But no joy with the window its still in the bottom of the door.
Found the 2 wires for the moter and undid them and then took the moter out by un doing 3 nuts. Was surprised how easy it came out with the window down. There was a bit of crap grease all around the moter so gave it agood clean. Put the 2 wire back on door , they go to a plastic part thats clipped into the door with another 2 wire.
The motor starts working. Put it back on with the window at the top now and the sort top worked on the button BUT after 2 goes at this the window get stuck at the bottem again.
Because i never used the switch i am thinking its

Sorry it the button by mistake.
Think its the part that stops the door when going down. Can use the window BUT not go all the way down otherwise it just stops there and will not go up.
Thanks for your help Lostkiwi.
Rob

 

[LostKiwi]

Can't see it being the limit switch. That just stops it going down past the end of the travel.
You could try testing the switch (it comes out easily) and filling it full of contact cleaner.
Operating the roof will make the window go all the way down so you'll still have an issue.

 

[roblloyd]

Can't see it being the limit switch. That just stops it going down past the end of the travel.
You could try testing the switch (it comes out easily) and filling it full of contact cleaner.
Operating the roof will make the window go all the way down so you'll still have an issue.

Which switc are you talking about? Is it the limit switch and if so were in the door is that? Do i just case the wires coming off that switch and thats it?
Sorry for all the ?s BUT i am just a beginner were electrics are concerned.
Do appreciate all the help you give, saves me money i just do not have.
Thanks
rob

Can't see it being the limit switch. That just stops it going down past the end of the travel.
You could try testing the switch (it comes out easily) and filling it full of contact cleaner.
Operating the roof will make the window go all the way down so you'll still have an issue.

Got it now, you mean the switch that controls the windows. Have not had that out yet because i was worried i would do damage to the wood.
Whats the best way of getting the wood out first because the switch will not come out without the wood coming out first. Any suggestions?
Rob

 

[LostKiwi]

No. the limit switch is in the bottom of the door.
When the window goes all the way down it tells the window control module (actually the roof control module but it also does the windows) to stop the motor. Remove the door card and you'll find it halfway along the door in the very bottom. Easy to remove and check/clean.

 

[roblloyd]

No. the limit switch is in the bottom of the door.
When the window goes all the way down it tells the window control module (actually the roof control module but it also does the windows) to stop the motor. Remove the door card and you'll find it halfway along the door in the very bottom. Easy to remove and check/clean.

Thanks lostkiwi
Will do that and let you know the outcome. Got to try to get it passes a M O T first ASAP.
Thank again
Rob