W124 E280 battery? ignition?

[Bolide]

From memory the tailgate RCL locking system has a separate loom with a plug for the sensor. I've not seen one of these fail like the other loom but there's always a first time. I don't think the RCL fault is linked to the window problems

I think front windows should work with the door open & ignition off on all late W124s. I suspect you have more than one problem

I believe there is a diode in a feed to the windows when the ignition is off but you'll have to find an accurate wiring diagram to find where the problem(s) lie

Nick Froome

 

[The Big E]

diode

Cheers Nick, it's an accurate wiring diagram i can't find. Television sent me a link with wiring diagrams but my e280 is not there so I'm looking at several similar ones and cross referencing. I'm not too hot with electrics but I'll have a go...it just takes me a long time. Television did at one time mention that DIODE but I can't find it. There's a diode marked at the back of the fuse box but it only appears to contain one of the ordinary fuses with the other position empty, it's the same on my E300 and that all works. That DIODE must be somewhere else.
I'm convinced that if I can find and change that DIODE all will be well...but what do I know!
Thanks again.

 

[The Big E]

A thought

Should I open a fresh thread for this as the battery drain is now sorted. It's the comfort control I'm trying to sort now. Any views on what action I should take?

 

[television]

The diode relay is up in a front box and is always the reason for this and when the doors are open.

At the top here http://www.autolib.diakom.ru/CAR/Mercedes-Benz/1991/300CE/SYSTEM WIRING DIAGRAMS/3758.pdf

A 001 542 78 19 RELAY
COMFORT SWITCHING

 

[The Big E]

Thanks Television, Please excuse my ignorance, is it the bit marked 'fuse box relay'. Am I correct in saying it will be behind the Battery? If so how big or small might it be? I'll have a search this afternoon.
Thanks to you all for your interest, I just wish I was a little smarter

 

[television]

Its 89 but the size shown is not always representative

 

[The Big E]

Thanks Television, that is the (relay) I mentioned earlier, it has two positions in it for the standard fuses. One position has a fuse the other position is empty, as is the one on my other car. I have swopped between cars and it makes no difference. Would this be just a fuse carrier for the DIODE that is located somewhere else I've cleaned terminals, replaced fuse, even put a fuse into the vacant position, no change. I'm convinced that it must be a broken wire in one or more of the door hinge boots.

 

[television]

That is quite possible, do check that the door pin switches are clean and working, I cannot remember if the drivers door one is a double pole

 

[The Big E]

All checked......many times. I just need to find that DIODE!

 

[television]

All checked......many times. I just need to find that DIODE!

It is in that little relay

 

[The Big E]

No, I'm sure it's just a fuse carrier. But I will check it again later.

 

[star]

Not read all this thread but the diode is plugged in on the underside of the fuse board if fitted on a 124 and on top on a 126 (poss position H???). has a small pull tab on it (grey or black)

 

[The Big E]

As you name suggests...you are a STAR
Can't thank you enough. I'm off to have a delve
Cheers

 

[The Big E]

diode

Hi, can't find that elusive diode
I've attached a couple of shots of the underside of the fuse board, nothing jumps out to me.
Any idea what size it might be? Thimble?, matchbox?, cell phone? it sure would help if I knew what I was looking for.
Perhaps I should buy a Morris Eight, the're more my era!
Regards

 

[star]

See those 3 tabs on the 1st pic, a bit like those in size as well, sometimes they dont have the pull tab, check the relay board too. Its been ages since I changed one. Not all 124's have it fitted, some have a comfort control unit under pas rear seat. The part number your looking for is 2105401181, bout 15mm in length and 8mm wide with 2 pins and a locating pin. ???

 

[The Big E]

Thanks Star.
Just off out now, I'll look later. It does have the unit under the rear seat....I am becoming convinced it does not have that illusive DIODE. Must be a wire fractured somewhere.
Regards

 

[television]

And I still say its all part of that relay up front, it is a solid state device

All references in WIS point to the relay, there is no separate diode fitted,,and there is not one shown on the wiring diagrams either.

Double checking again in WIS no mention of any diode just the K24 I would also check the fuses

 

[Bolide]

Have you unscrewed the surround of the fusebox and removed it? Under the back section are the relays, lamp warning relay and possibly the elusive diode...

It'll be small (or, rather, it has no reason to be big) and should have two pins on it

Broken wires by the door hinges are a possibility. Sometimes you find the windows will work with the door open at one particular position - that's the giveaway. Same with the tailgate - sometimes the number plate lights go out when the tailgate is half open

Nick Froome

 

[television]

There is no mention of any diode in the checking procedure for this, yes its in the description, but is built into that K24. The circuit diagrams prove that

 

[The Big E]

Thanks for your interest guys.
Television
I'd come to the conclusion that there was no seperate diode. I did swop that relay (A001 542 78 19) for a known working one....no difference but I'll get another off e-bay. I did spin & check the fuses.
Boldie
Yes, I've been under the fuses and the relays....nothing. I have pushed and pulled the wiring boot on the door whilst holding down a window switch....nothing BUT I've not done the tailgate, I'll try tomorrow. Have to get 'er indors to help, me arms ain't that long
Television
By K24 do you mean relay A001 542 78 19 the white/clear cube one?
I'll have to have another go at that WIS. Tried it a couple of times but I do seem to struggle with it
Regards