I forbindelse med et indlæg i køb og salg, vælger jeg lige at oprette en tråd vedr. dette, da indlæg i køb og salg jo slettes over tid. Det drejer sig om motorne til elruder bag, som nogen kommenterer at det er en svaghed på W124, og jeg har hørt andre sige det samme. Det er min personlige mening at motorerne brænder af, fordi bagvinduerne ikke bruges nær så tit som frontvinduerne. Dermed gror forbindelserne fast, og motoren bliver mere og mere overbelastet, hver gang ruden endelig bruges. Jeg er slet ikke i tvivl om at frontmotorerne også kan brænde af grundet manglende smøring, men kun reddes fordi hele mekanismen ikke når at gro nær så meget fast som de bagerste ruder, fordi ruderne bruges mere foran. Så jeg tror ikke at det er løsningen bare at skifte motoren og tro alt er godt.

Mercedessource anbefaler også smøring af elruderne, som Kent betegner som "really neglected". Så måske kan motorerne reddes fra fremtidig defekt, ved "blot" at adskille døren og smøre mekanismen, og det slet ikke er en svaghed som sådan, men manglende vedligehold over tid grundet udtørring af den originale fedt, som ender i en generel defekt på serien. Faktisk anbefaler Kent at rude-regulatoren smøres ca. hvert 2 år, med en syntetisk fedt. Det er noget jeg skal have gjort på min egen også, for jeg kan høre motorerne arbejde lidt hårdt på nogle af ruderne, når de er ca. halvt nede.

 

God pointe.
Men gummilisterne "kan" også være årsagen da mange lister tørre ud og filtet forsvinder på inner siden mod ruden, og så køre ruden op og ned af en gummiliste kant, frem for en filt liste der jo glider væsentlig nemmere. men klart meget af det fedt de føst med tørre ud og det skal jo eftersmøres, men 2 år er lige krakilsk nok. en god fedt kan sagtens holde 5 år hvis ikke 10 År som det jo nok også har gjort originalt.

Meget udbredt er også tandkrænsen knækker 1 tand af som er den tand den "hviler"/Presser" i mod når ruden er rullet helt op og dermed står i spænd mod tanden. så knækker den med tiden og så kan ruden ikke rulles helt i top. dette kan mindskes ved lige at give den et lille hurtigt klik på nedrulnings knappen så ruden ikke står i spænd og slider og gnaver unødigt under kørslen og smækken med døren uden det går ud over tætheden.

 

Ja, det er nok korrekt - det er flere ting som kan spille ind. Jeg var i øvrigt ikke klar over at tanden kan knække, så det lille trick skal nok blive husket på matriklen.

Er der i øvrigt nogle som ved om motoren er ens for og bag (og venstre til højre)?

 

Man kan i øvrigt reparere motorerne, hvis de fejler... det er nemlig ikke motoren i sig selv der fejler, men sikkerhedskredsløbet i motoren som brænder over (som det skal hvis man holder knappen nede for længe, selvom ruden er oppe eller nede). jeg har sakset lidt fra peachparts' forum, hvor en bruger beskriver en reparation af motoren.

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I've seen lots of DIYs on removing, repairing, and reinstalling window regulators in the W124 - back and front. I haven't seen any on the motors. If I missed one somewhere, my apologies for the double post.

Three of my 4 windows failed, the drivers' side still worked. My conclusion is that they should be used regularly, not "saved", to keep in top working condition.

Back to the motors - there is a part on these motors that appears to be a safety circuit that breaks contact if the motor is put under excessive stress (such as holding down the switch when the window is fully closed or open). This component failed on all three of my windows by becoming corroded inside and no longer making sufficient contact to close the circuit. It's made by a company called "Otter", has "Made in Britain" embossed on it and is about an inch by 1/2 inch by 3/8 inch (from memory) and either black or white. It mounts inside the motor opposite the side where the power cable enters the motor. I found no reference to the part, part number, name, etc. on the web. If anyone has a lead on this part as a replacement, please post it here.

Fixing the motor is simple. Just solder a heavy copper wire (16 or 12 gauge solid copper house wire works fine) across these contacts to bypass the faulty part. See the attached pictures - the first is of the contacts (they're flat and a little farther apart than the contacts that are on the side where the wire enters the motor. The second is with the wire soldered in place (use electronics type flux to get a good connection). The third picture is what NOT to solder across or you'll short the incoming wires.

First things first - note which way the wire/motor is oriented with respect to the regulator so you get it back together with the wire on the right side. I am not sure but most likely it can be done wrong. This is more important on the front since the wire is very short.

You can remove the screws that hold the motor to the regulator (25 torx I think) and twist the motor enough to access these contacts. Solder away and you have a 50/50 chance that the motor will now run. If it doesn't, it's probably because the grease is all dried out. Using 12v leads, hold the regulator in a vice (or between your feet) and apply power while at the same time pulling the motor out. If you have the voltage + and - correct, and it runs, it'll back right out (or reverse the connections if you didn't get it right). You can then proceed to completely overhaul the motor and regulator gears. Note that there is no reason to remove the slotted screw that goes in the end of the regulator (where the end of the motor shaft will be).

Also note that by bypassing this part you are likely circumventing some sort of safety mechanism. I valued the motor working more than the "safety" feature and made the decision accordingly - you'll need to consider this decision on your car. As long as you don't have a 2 year old that is prone to holding down buttons and/or you keep the ice cream and cola out of the switches that might cause them to stick, I'd think that you'd be ok. Make this repair at your risk, however.

Back to the motor... If it doesn't back out or run, don't lose hope. Just keep working it by hand. It'll eventually free up enough that the gear will allow it to be pulled straight out of the gear (worked for me on both front and rear - only one of the 3 motors worked immediately upon the bridging trick). Worst case, proceed to disassembling the motor (with the sand filled hammer) and get the case off, then you can "unscrew" the worm gear by hand.


Overhauling the motor:
To overhaul the motor, first remove the tape holding the wire to the case. Then hold the metal body of the motor with the motor pointing downward and (ideally) use a plastic sand-filled hammer to tap on the rounded end fairly forcefully. This will jar the stator and loosen up the white plastic piece, allowing you to wiggle it out, exposing the guts of the motor. Carefully remove the stator (main part of the motor, if I've got my terminology correct) and use brake cleaner and/or a wire brush to remove all of the oil and rust from the gear. I put a fine wire wheel in my drill press to polish it up once the grease was all out. Use fine steel wool on the ends of the shaft (not the wire brush) - the smoother the better since these are what holds the shaft when it's spinning. Also use contact cleaner or something similar to clean up the copper contacts on the shaft but be careful with them. I also used a small curved metal file to lightly sand down the brushes to freshen them up.

If you did a lousy soldering job in the tight space, now's the time to spiff that up. Don't get it too hot for too long, it's just mounted to plastic. Also, using an ohm meter test that one wire goes to one brush without resistance and the same with the other. Also verify that there is infinite resistance across the black and green wire with the stator removed. This will ensure that you didn't create (or there wasn't already) a short. If this isn't the case, it must be corrected or the motor won't run, fuse will blow, etc.

To reassemble the motor, move one carbon spring-loaded brush (in the plastic "electronics" end) to one side and put the stator through the hole at an angle to hold the brush in place against the copper contacts ring. Then use a small screwdriver to move the other brush out of the way and slip the shaft/stator back into place. Holding the worm gear and shaft tightly, apply a tiny bit of wheel bearing grease to the opposite smooth end of the shaft by the windings and reinsert it in the case. It'll stick to the metal on one side or the other - keep the plastic part in place while you work it back to where it belongs (grip the shaft tightly against the plastic and your hand will hold the plastic in place while you push it all back together. Make sure that you've got the wire entry point on the proper side of the case or it won't go back in. Once the motor is in, it should spin freely more or less although it won't be perfectly centered until it's back in the regulator housing. The plastic should be slighly recessed in the metal casing.

Center the motor shaft as best you can in the plastic top (without the regulator) and go hook it to the battery. It should spin fast and fancy free. If it does, retape the wire in place. If it doesn't, you might be SOL at this point but one possibility is the brushes. If the brushes are totally worn down and there's no spring left to them, you can go to a good auto parts store and buy new ones probably but I didn't have to deal with this issue... If you do have to go this route, and you can't find the correct size, buy slightly larger ones and just file them down to fit. There's not much else to go wrong with a motor except a short in the actual windings. One other thing to try is to take a razor blade and lightly cut/clean the lines between the copper contacts at the top of the windings - maybe some of these shorted across each other.

Last, clean and reinstall the rubber shaft seal where the motor shaft/worm gear enters the regulator, put a tiny amount of grease on the smooth end of the motor shaft that enters the regulator, pack the worm gear with wheel bearing grease, and reassemble. Double check your wire orientation vs. the regulator gearbox. If you put the gear in already, reverse the procedure of removal and hold it between your feet (or a vise) and apply power briefly when pushing it into place. It should "drive" itself in. If you didn't put the gear in, just slide it in. If the motor gasket is shot, you could use a bit of silicone/gasket maker to seal it. Seat it snugly and reinsert screws and tighten them down.
"

Jeg tænker her at der kan være røget RIGTIGT mange regulatorer ud, som egentligt kunne have været reddet på denne måde... hvis man er nervøs for at have fjernet den eneste sikkerhed i kredsløbet (der er dog også en sikring), kan man købe en løs Otter-kontakt, og sætte i døren - http://www.ottercontrols.co.uk/

 

Der bør være en af disse Otter-typer, som kan erstatte den originale i motoren (man kan klikke på de andre typer også). http://www.ottercontrols.co.uk/pb-series.html

Billede af den originale i motoren, er vedhæftet!