C124 window issue

[daibill]

My 95 c124 is coming back to life slowly. Gave the fuse box a good clean with a small wire brush on a Dremel and coated all connections with electric grease.. Both rear windows now work when they didn't but the fronts still refuse to.
I removed the door panel on the drivers side and can see 12v is being delivered to the connections screwed to the door frame but no movement from the motor..

Question is, are the motors serviceable or am I looking for new motors which seem to be rare?

Thanks

 

[hotrodder]

The windows use a switched earth so having 12V at one of the motor terminals just means that the +ve feed is OK.

Just to clarify when you say no movement from the motor you definately mean the motor and not glass? It's not uncommon for the motor to run but not move the glass as the regulator teeth have worn down and 'stripped' but as you can hear the motor wirring away i'm sure this isn't the case

Are the front windows dead in all situations i.e. ignition on, ignition off door open, convenience function (closing/opening windows by locking/unlocking the car)?

Mercedes Benz Model 124 - M104 Maintenance Manuals 72 (doors) covers removal of window regulators etc, 82 (misc body electrics) has wiring diagrams for the windows and convenience module but is American so ignoring the obvious RHD/LHD thing (fuse box is on the other side etc) still might not be 100% accurate

 

[daibill]

Thanks for the reply..

I get 12v when I operate the window switch but do not see any movement of the regulator as the card is off or hear any noises from the motor... Have tried ignition on/off door open and closed but the central locking is stuffed (pump failure I think) so cannot test that part. Convenience relay is clicking when the switch is operating and that's when I am getting the voltages..

 

[dinoy]

hand on motor can u feel any clicking movement.

depending on model of w124 motor from 10-30 (coupe/convertible most expensive) but do check europarts gsf they may have

many sold on their own, or people breaking cars

 

[hotrodder]

I dunno how servicable the motors are but on my s124 they're definately bolted together rather than assembled with crimped/rivetted joints so should be easy* to dismantle. I've never needed to go that far as the only window issues i've had to deal with is knackered/stripped regulators

* Easy applies to unbolting the motor from the regulator and taking the covers off it (torx screws for that bit). The difficult bit is that the 1st step in the instructions for removing the regulator and motor from the doot is to lower the glass When the glass is stuck in the up position you're working blind inside the door, been there with mine (aforementioned stripped regulator teeth) and it involved lots of swearing

Personally i'd disconnect the power, give the motor a good thump and then hook up a temporary feed (bypassing the switches/relays etc) on the offchance. Longshot but you never know

 

[dinoy]

i always replaced the unit, u still have not indicated on the model of the car in question is it saloon estate coupe.

i suggest u look for replacement if new none oem is cheap get it as it warrants 1 year guarantee.

as for fixing i am not sure i have seen one fixed for less than 2nd hand replacement

 

[daibill]

It's a 95 e220 coupe..

Been to it this morning and give it a tap with a persuader also put 12v from a battery to it and no joy.. No clicking from it either..

Look like the wallet is going to get a bit lighter..eBay not showing many..

Is the motor separate to the regulator or are they combined?

 

[Philbask]

The motor assembly is removable without the regulator (but take care and support regulator / glass) The motors have a switch inside (not sure but think it's a bi-metallic arrangement to cut the power on overload) it can with a little digging be 'got at' and reset..... but if you do need a new motor then it is just a motor you will have to get rather than the entire assembly.

 

[daibill]

Thanks for that.. Looks like I will have to drill some rivets to get it out so will have a look on the weekend.

Thank you all for your help. Will report back on the weekend.

 

[Sp!ke]

I had some success with stripping the motors on mine and cleaning them up before reassembly with new brushes from an electrical supplier.

Do check it's not simply faulty switches first and be warned, those rivets aren't your average rivets. They are huge things that need to be ordered as you won't find them in your local diy store. You will also likely need to hire a big rivet gun (unless you have access to a compressor based gun).

You can with a bit of care, swap the rivets for suitably sized nuts and bolts should you struggle with the rivets.

 

[daibill]

Positive it's not the switches as I can see voltage to the motor when pressed.

Define huge rivets? What size are we talking about?

 

[dinoy]

Positive it's not the switches as I can see voltage to the motor when pressed.

Define huge rivets? What size are we talking about?

we replaced in many coupes and screw and nuts fitted it back delicate job but done

if u r near london get one of the breakers of coupe to sort out the motor and bring it vinod who is expert in these things and had replaced mine.

if u are checking was mentioned check the mechanism for the teeth if filed u might as well change both at the same time

 

[hotrodder]

Define huge rivets? What size are we talking about?

72-185 in the link i posted gives a drill size of 6mm for removing the old rivets and mentions a Gesipa HN-1 for pulling the replacements which is over 1/2 metre long overall to give the leverage needed for pulling blind rivets upto 1/4" (6.4mm) dia or maybe even larger

 

[dinoy]

OE Quality Mercedes-Benz | Euro Car Parts UK?s No.1 Car Parts Retailer

 

[hotrodder]

Typical eurocraparts, nearly £20 more expensive than 1247203046 or 1247202946 list price from Mercedes, over £30 more spendy than MB Inchcape. Motors are sold seperately and even more expensive, used ones here (for part numbers more than anything) Window regulator, Window for Mercedes 124.052 (320CE / E320) the pinion gear on the motors doesn't seem to wear out like the regulator, at least that was the case for the 2 regulators i've repaired by welding

2nd hand regulators are often a waste of time for example http://www.ebay.co.uk/itm/Mercedes-E-Class-W124-Door-Window-Regulator It's a saloon/estate example which is showing the usual signs of wear (several teeth worn almost completely away at the closed position), only really useful for a spare to repair by welding and regrinding the knackered teeth before taking the door apart. Assuming the assist spring isn't too tired

 

[dinoy]

i done the same with welding and grinding, but interesting what would the price be for the motors new looks like mercedes being the only ones no replacement or rewired, might be worth approaching electrical shop to try to get them fixed as they are rare and pricey.

try robert walker if he has some, i think even the motors are special ones for coupe convertible ones

 

[daibill]

I'll take a look on the weekend. Have read that there is a safety feature built in that may have tripped them. If they can be reset or bypassed then hopefully they will come back to life..

 

[hotrodder]

i done the same with welding and grinding, but interesting what would the price be for the motors new looks like mercedes being the only ones no replacement or rewired, might be worth approaching electrical shop to try to get them fixed as they are rare and pricey.

try robert walker if he has some, i think even the motors are special ones for coupe convertible ones

Yeah, different part# with a 129 prefix for coupe/convertible. Around £200 new from MB based on the part numbers in the link i posted. Just looked up the price for estate/saloon front window motors, £291 list!!

 

[daibill]

Been a while but have an update. As well as the front windows not working the central locking pump had failed.. Took a while but Obtained a used one from Germany and installed it today..I now have working central locking however the front drivers window has now burst into life as well! Nothing from the passenger side but haven't looked at that side yet. Closure is working as well. This was not working before the new pump went in because I tried it first.

Did not know the 2 were connected...

Anyway I think that's a result

 

[LCHutton]

I'm having problems with the RF Window Motor. (see here for details http://www.mbclub.co.uk/forums/elec...4-front-window-regulator-saloon-estate-2.html)

Using the above w124 link I found the wiring diagram but I do not understand enough about electrics to be helpful. In addition, hotrodder said this motor uses a switched earth so I have no idea how it is supposed to work.

When I press either the open or close switch, the motor makes one click but doesn't move. It did the same thing when the motor was not connected to the regulator gear. I tested the voltages and found the following:
KEY OFF
5 millivolts from green wire to ground and 5 millivolts from black wire to ground
KEY ON - without pushing the switch
12.5 volts from green wire to ground and 12.5 volts from black wire to ground
KEY ON - Push either the Up or Down Switch
UP - the 12.5 volts drops to zero on one of the wires
DOWN - the 12.5 volts drops to zero on the other wire

This window is rarely used so I'd rather have it held in the up position than spend any money on a new motor but if the fix is simple I would try it before re-installing the door panel.

Any suggestions?

Are the above voltages normal or is there an issue with the switch or somewhere else.