w124 combination switch replacement

[mattc]

Am replacing the above but have a slight problem.

The unit in the car (a 95 e320 estate) is numbered 124 540 1145. I have been given a replacement 2nd hand one where the number is 124 545 0224. Is there any difference or is the replacement one an earlier one and the number has been superceded (when I plug the numbers into Inchcape site only the 1145 one comes up)

There is a secondary issue in that on the number 12 pin of the unit a 2nd wire has been soldered on (I 'think' its aftermarket but could be wrong). What is the number 12 pin for and can my neighbour who is handy with a soldering iron simply attach the same wire to the replacement switch?

I am changing the unit as periodically the indicators/wipers will not work -both on intermittent and permanent settings. I will also be asking my neighbour to check the N10 relay for dry joints.

 

[scillyisles1]

On the official MB EPC, part number A1245450224 does not exist which makes me think that the part number is wrong.
Part number A1245401145 is the correct part number for the multi function indicator switch on an E320 and according to the EPC has not been superceded.

 

[mr. shr]

I would get the right part number if I were you.
Ring your dealer and ask for parts dept. Tell them the part number from your existing item (or just give them the car VIN and say you need a new combination switch).
They will tell you the correct part number.
Will probably be about 50 quid.

(Or just pm me your VIN and I'll look up the right one for your car.)

 

[mr. shr]

Ouch!!
Just looked up A124 540 1145 and that is into three figures!!

I've replaced combo switch on my W202 and S211 and sure I didn't pay more than 50 pounds from Stealer.

 

[mattc]

As I say I suspect the replacement one is from an earlier vehicle. The part is pukka (I trust it given the source it came from). Think I will ring merc and ask them if its available or has it been replaced by the other number.

Given the price I am reluctant to buy a new one.

Does any one have a wiring diagram for the multi stalk by the way?

 

[grober]

As far as I can make out pin 12 is a lead that goes to the front wiper motor/control. A second lead from pin 12 normally goes to the rear wiper intermittent control [ on an estate]----my deduction is that the switch you have is from an early saloon and the extra blue wire was added to power a rear wiper. ---- but this is just speculation on my part. This info was gleaned from a variety of sources- if I had a circuit diagram I would post it sorry.

 

[mattc]

That makes some sense Graeme. Will get my neighbour to solder it tomorrow in situ and do the N10 at the same time.

 

[Dec]

...periodically the indicators/wipers will not work -both on intermittent and permanent settings. I will also be asking my neighbour to check the N10 relay for dry joints.

I would definitely check the N10 relay first, what you say above would point to that as the problem particularly if speeds 2 and 3 work normally EXEPT that the wiper blade doesn’t park when the stalk is turned OFF.
See… http://www.mbclub.co.uk/forums/favourites/93685-how-repair-resolder-relay.html

Dec

 

[mattc]

I would definitely check the N10 relay first, what you say above would point to that as the problem particularly if speeds 2 and 3 work normally EXEPT that the wiper blade doesn’t park when the stalk is turned OFF.
See… http://www.mbclub.co.uk/forums/favourites/93685-how-repair-resolder-relay.html

Dec

too late - I had already disassembled the steering wheel/column. I should also add that a few times now the indicators would not work at all despite being fully engaged.

 

[Dec]

That’s the nature of an intermittent fault, sometimes things are working, an hour later the are not.

The hazards and indicators + the intermittent wiper + the rear demister are all controlled in the N10 relay, it can be difficult to catch all 3 not doing their job at any given time, so do the wiggle test on the relay.

The previous owner may well have been trying to fix this fault, this extra wire on the stalk indicate someone was at that fault before.


Dec

 

[armandjones82]

If you could have a good Combination Switch replacement to find for, go for it! There are a lot of resources here, and you need to really find the right one. Together with the part number and whether it is compatible to your car or not. I know you can find one by all the help people here would post for it!

 

[mattc]

Guess who has just found a broken N10 relay in exactly the spot identified in the earlier link! Will repair and replace everything later

 

[Dec]

You’re the 3rd person to confirm that it is that particular joint that is broken, it seems to be the main power supply to the N10 as it knocks out all 3 relays, intermittent wiper, indicators & hazards and rear screen demister.
Thanks for the feed back, always useful to know the cause and the cure of a fault.

Dec

 

[mattc]

Put the replacement indicator on and the resoldered N10. Everything works correctly now including indicating left when you just knock the stalk up without engaging the switch. This had stopped working before so happy about that