wiring diagram for them, 2491500.pdf

I do believe I'd first test those fuses B and C with an ohm-meter, then I'd check for power at the motor connector of each extender's controller (connector 2 pins 4 and 7) when you think they are trying to cycle.

 

The seat belt presenters are wired differently on the coupe and the cabriolet. For the coupe, the relevant fuses are B and C whereas on the cabriolet they are Fuse C and Fuse 1. On the coupe, the seat belts don't "present" until the key is turned to the "run" (II) position whereas on the cabriolet, they "present" when the key is in the "accessory" (I) position. Replace Fuse C and Fuse 1 prophylactically. If that does not solve the problem, remove Fuse C and then try and (gently) pull the presenters. I have seen the motor "fight" you when you try to pull them while powered. If you can pull them out, replace the Fuse C with the presenters about half way out and the doors closed and then see if the cycle normally.

- FD

 

The seat belt presenters are wired differently on the coupe and the cabriolet. For the coupe, the relevant fuses are B and C whereas on the cabriolet they are Fuse C and Fuse 1. On the coupe, the seat belts don't "present" until the key is turned to the "run" (II) position whereas on the cabriolet, they "present" when the key is in the "accessory" (I) position. Replace Fuse C and Fuse 1 prophylactically. If that does not solve the problem, remove Fuse C and then try and (gently) pull the presenters. I have seen the motor "fight" you when you try to pull them while powered. If you can pull them out, replace the Fuse C with the presenters about half way out and the doors closed and then see if the cycle normally.

- FD

Hello FD, I came across your post when searching for a solution to the seat belt presenter problem on the same vehicle ('93 300CE Cab.). I tried your suggestion of removing fuses, pulling out the presenters and replacing the fuses, all with the doors closed. It worked once. Subsequent attempts have not been successful. The presenters retract as soon asa the fuses are replaced. Interestingly, the interior dome light remained on while the fuses were removed.

I recently had both door jam light switches replaced. Is it possible the new switches are the problem? Perhaps the wrong part for my vehicle?

I live in San Francisco and would love to find a shop that has expertise in this era vehicle.
Thanks in advance.

 

oops, I didn't see 'cabriolet'. musta been too early in the 'morning' (cough, noon).

cabriolet version: 2491400.pdf

 

Thanks Floodbydust! That did the trick. Thanks also to Volvo745 for your help and the wiring diagram.

I replaced the fuses. This did not fix the issue. I removed Fuses 1, B and C, removed the rubber head piece at the tip of the arm and gripped the ends of the arms with some needle nose vise grips until they pulled out about half way, as you suggested. I still had to pull on them harder than I thought I would need to, even with the fuses out. They did not retract when I re-inserted the fuses, but they did extend fully when I turned the key to "run."

Both presenters are working fine now. I am greatly relieved that I didn't have to take things apart to address the issue.

Any ideas how to avoid this the next time I need to replace the battery?

 

Thanks Floodbydust! That did the trick. Thanks also to Volvo745 for your help and the wiring diagram.

I replaced the fuses. This did not fix the issue. I removed Fuses 1, B and C, removed the rubber head piece at the tip of the arm and gripped the ends of the arms with some needle nose vise grips until they pulled out about half way, as you suggested. I still had to pull on them harder than I thought I would need to, even with the fuses out. They did not retract when I re-inserted the fuses, but they did extend fully when I turned the key to "run."

Both presenters are working fine now. I am greatly relieved that I didn't have to take things apart to address the issue.

Any ideas how to avoid this the next time I need to replace the battery?

My theory is that as the retractor mechanism wears over time, it overshoots the stop upon retraction. This can really be an issue if the little belt triangle is not fully seated or warped/damaged. Under normally conditions this is not a problem because the controller "remembers" that the arm passed the inward stop so it knows the position anyway. When you kill power to the module through something like replacing the battery or running it flat, the controller forgets where things are because the microswitches are not correctly reporting the arm position due to the overshoot. The way to let the controller figure that out is to pull the arms out a bit so the "in process" microswitch gets activated. After that, it knows and stores the position.

As for prevention - make sure the triangle is firmly seated on the arm and not damaged. Otherwise you may have to do the same thing again.

 

Yes - two conditions must be satisfied for the controller to "present" the belts when you start the car. One, the door switch must detect an opened door, and two, the belts in the corresponding seat must not be buckled.

Keep your old module as I believe they are NLA for the cabrio. I do get back to SF to visit family from time to time, but not often enough!

 

Thank you very much for taking time to address my little, yet aggravating, problem. Did you mean to say the door switch must detect a "closed" door?
I'm sure your SF family would enjoy a visit!

 

Welcome to the forum
For having found the W124 forum section for your car.

Please click Complete your Profile to add 1993 300CE, so it will show next to every future post under your avatar.
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FYI, the forum index is grouped according to chassis / platform designation, usually one letter followed by 3 digits / numbers, and sections cover all engine versions the chassis came with.

The forum sections archives have a wealth of DIY / technical information.
When researching an issue in your section / before posting, you can also Search the
W124 E,CE,D,TD Class forum archives via the 'Search Community' box on top..

The stickies on top of the 'Welcome' section will help to navigate the site.

 

It must see the door closed, then open (sets module to cycle), the close again (executes the cycle). The belts will stay "presented" for about 10 seconds if you do nothing, but the presenter will close before then if the module detects the seat belt is buckled.