Mercedes seat belt presenters..

[SmokeEm]

Any idea how they work? My drivers side works fine but passenger doesn't.

Ive been told that the door switch is the feed but the interior light goes on and off when the door opens so that means it cannot be that? Or does it have other functions? 

All the specialists just seem to want to supply a replacement at well over £100 and there is no way I would attempt to fit one with my skills! Anyone have a simple way to test where the fault lies? 

[bortaf]

Do they only come out if somone is sitting in the seat? if they do it could be the seat sensor ? not 100% sure if they have a seat sensor though ?

[SmokeEm]

Oct 12, 2015 19:04:26 GMT bortaf said:

Do they only come out if somone is sitting in the seat? if they do it could be the seat sensor ? not 100% sure if they have a seat sensor though ?

Again I am confused as there Deffo is a seat sensor but it must be working because the auto airbag light thing goes out when seat is occupied? 

[colnerov]

Hi, This is only a guess but if it worked on the door switch would the presenter block access to the back seats for would be passengers? So I think there might be a second seat occupancy switch, and possibly a switch on the seat back tilt mechanism to stop the presenter deploying with the door open and seat back tipped forward. Then with the door closed, seat back upright and seat occupied then the presenter deploys. You could prove this with the drivers seat in different scenarios.

Colin

[Battles]

I typed a big reply about how the W124 seatbelt butlers work but I guess it would be more relevant question to ask if the systems are similar and if they work in the same way?

Two push switches in the door frame, a sensor in the seat, stuff like that?
I wouldn't be surprised if the W140 had some massively more complex way of doing it.

[SmokeEm]

Deffo too complex for my tiny brain and mahoosive fingers. Think I will find a local Merc specialist and get them to diagnose the problem when doing the rear discs in the spring.

[SmokeEm]

Oct 13, 2015 14:27:07 GMT Battles said:

I typed a big reply about how the W124 seatbelt butlers work but I guess it would be more relevant question to ask if the systems are similar and if they work in the same way?

Two push switches in the door frame, a sensor in the seat, stuff like that?
I wouldn't be surprised if the W140 had some massively more complex way of doing it.

I didn't realise they have two door switches? Might be worth switching them around as the courtesy light comes on but butler doesn't. If I swap them over for each other, that would work wouldn't it? Or are they not identical? 

[colnerov]

Hi, door switches usually work by earthing the circuit, so it might be worth making sure the switches (if there are two) are grounded properly.

Colin

[Battles]

Oct 13, 2015 14:35:13 GMT SmokeEm said:

Oct 13, 2015 14:27:07 GMT Battles said:

I typed a big reply about how the W124 seatbelt butlers work but I guess it would be more relevant question to ask if the systems are similar and if they work in the same way?

Two push switches in the door frame, a sensor in the seat, stuff like that?
I wouldn't be surprised if the W140 had some massively more complex way of doing it.

I didn't realise they have two door switches? Might be worth switching them around as the courtesy light comes on but butler doesn't. If I swap them over for each other, that would work wouldn't it? Or are they not identical? 

The W124 has two switches, does the W140 have two as well?

I had a decent procedure for testing the butlers I pulled from a car I was breaking. I connected them to my own coupe (which had known good presenters and controller) and could use the door switches in a fairly unscientific way (which is to say I had no effing idea) while kneeling on the seat to make the presenters run and perform a basic in/out test.

I took this to mean that when the switch was operated AND the seat sensor was engaged that it assumed the door had been closed and the seatbelt was required. It did this after a short delay.
Does that sound plausible?

[SmokeEm]

colnerov Will Do. Thank you.


@battles It does yes, I will have to have a play won't I lol