Seat Belt Presenters - PeachParts Mercedes-Benz Forum

escosys · #1 09-27-2016, 06:20 AM

Hi
I recently bought a 300CE and changed the passenger side presenter, which now works ok, except it always presents, whether there's a passenger or not, and retracts after about 30 seconds. The driver side retracts as soon as the belt is buckled.

I guess (please correct me) there are 2 switches, one to detect pressure on the seat, the other to detect the seat belt in the buckle. I suspect these are in series, the seat belt switch normally closed, and the seat pressure switch normally open. The passenger sits down, the belt presents, engage the belt and the circuit breaks, and the belt retracts.

Can someone please confirm/correct my thoughts? A bonus would be the part numbers of the switch(es).

Ferdman · #2 09-27-2016, 08:50 AM

escosys, I own a 1991 300CE and removed the fuse so the seatbelt presenters do not work. They are a nuisance, in my opinion, and only confuse the occasional passenger who is unfamiliar and not expecting the presenter. It's a simple matter of reaching your hand back, palm down, just above the door sill and grabbing the seatbelt. In my car the trim piece in the rear pod was loose, and the seatbelt presenter only compounded the problem.

duxthe1 · #3 09-27-2016, 08:59 AM

Its only supposed to present if the passenger door is opened. The switch for it is in the door jamb. It retracts when the seat belt is buckled or it times out.

escosys · #4 09-27-2016, 11:04 AM

So there's no sensing of a passenger in the seat?

duxthe1 · #5 09-27-2016, 01:22 PM

nope

anziani · #6 10-01-2016, 11:58 AM

Wait a minute, guys. I don't know if the '97 CL500 and 600 are different than the CE series but in both of those cars two things have to happen. 1) the door has to open, and 2) there has to be weight on the seat. This can be a bag of groceries or a six pack. I had a CE320 at one time but honestly don't remember how they worked. Your manual should certainly give you that information.
I've had trouble only once with the three cars that had presenters and it was a simple fix. There is a cheap plastic gear that wears out. There is a metal replacement found on Jim Forgione's great website.
Anziani

duxthe1 · #7 10-01-2016, 12:54 PM

Quote:

Originally Posted by anziani

I don't know if the '97 CL500 and 600 are different than the CE series

They are, significantly.

syljua · #8 10-03-2016, 07:53 AM

Quote:

Originally Posted by anziani

Wait a minute, guys. I don't know if the '97 CL500 and 600 are different than the CE series but in both of those cars two things have to happen. 1) the door has to open, and 2) there has to be weight on the seat. This can be a bag of groceries or a six pack.

No, that's not the experience I have with mine 98 CL500. When
I let passengers off, upon shutting the door, the presenters always extend,
regardless of weight in seat or not.

I have not seen any circuit drawing or sensor reference to support
statement 2 above, either.

br,
syljua

anziani · #9 10-01-2016, 02:00 PM

Well of course the cars are different. I meant the seat belt operations.
Anziani

duxthe1 · #10 10-01-2016, 02:34 PM

I did too. The CE has nothing in the seat related to the presenters aside from the seat belt buckle switch.

anziani · #11 10-03-2016, 10:50 AM

syljua, Yes my '97 Cl600 does the same after the bag of groceries is removed. The question was do the CE series act the same? Apparently not from these responses. My old CE320 is still in the area. I'll track him down and take a look.
Anziani

Kestas · #12 10-05-2016, 01:28 PM

I've had at least three seat belt presenter control modules in my car. The issue in my car is that water can get in (cabriolet), and it pools under the right rear passenger seat, drowning the module. Because it is charged with electricity and made of many dissimilar metals, corrosion sets in rapidly and ruins the module. The one I have now is a good one. But I took it out of the car because water still pools under the seat and I don't feel like drilling drain holes in my car.

dynalow · #13 10-05-2016, 01:51 PM

I recall reading a post here years ago where the author said he got a seat belt clip from a wreck and would clip it in the latch to keep the presenter from extending. My driver's side presenter hadn't presented itself in years, until once this summer it actually came halfway out. I've taken to fastening the belt before starting the car. Can't stand to hear the motor run and no arm come out.

Nothing at all on my passenger side.

anziani · #14 10-05-2016, 01:39 PM

Kestas, That certainly sucks! Any way you could relocate the module?
Anziani
'97 CL600 58K

Kestas · #15 10-05-2016, 04:31 PM

Quote:

Originally Posted by anziani

Kestas, That certainly sucks! Any way you could relocate the module?
Anziani
'97 CL600 58K

I tried placing it in a bag. That didn't work. There was one incident where my car was parked in a driving rain, and the people picnicking nearby told me the seat belt presenters were going crazy. I quickly removed the rear seat, disconnected the module, and shook the water out of it as best as I could. I never put it back in. It's available for the next guy should I ever decide to sell the car.

I did spray the electronics within the control unit generously to coat them with lacquer. I would recommend anyone with a working unit to do so, if it hasn't yet corroded. The only trick is to make sure to mask off the relays. They are the only moving parts.

The part number for my control unit is 140 820 25 26.