W140 ACC apirator - how to replace?
 

How do I get to the aspirator in the S420?

Thanks,
Sixto
95 S420
87 300SDL

Your car may be different, but in my W124, it's behind the passenger side vent.

The dealer sells little sticks that you insert into each side of the vent. There are tabs that the sticks go into. You pull the tabs toward the center of the vent, and the vent pulls right out. You can reach in with your hand and pull the motor out.

You can use any long, thin object with a pointy end, like an awl, ice pick, skewer, etc. in place of the dealer tool.

This one's in the dome light assembly. At least that's where the noise is coming from.

Sixto
95 S420
87 300SDL

Sixto, if it is similar to the late 126's the interior temp sensor is in the dome lamp assembly and the aspirator motor is buried in the passenger side dash. Remove the lamp assembly and see if there is a black plastic hose running from the assembly toward the passenger A pilar.

I will take a quick look at the EPC for the 140 and see if I can narrow down your search.

Sixto, it was a slow search through the EPC. I did find the aspirator but not the mounting location. The part number is 140 830 00 08.

Not familiar with the term "aspirator", but if you're looking for the small fan/internal temp sensor for the climate control, it is in the dome light housing.
You have to remove the dome light housing from the roof area... once you have it out, you'll clearly see the fan mounted from the back.
I've attached a pix of what it looks like.

Here's what it looks like from the back of the dome light housing.

Thanks Ken. I guess I wasn't specific. What I need to know is how the dome light assembly comes off. The 126 dome light is held on by clips and hinges down as Mike taught me sometime back. From your picture, it looks like there's a screw in the left and right dome light wells. Anything else to release before it drops?

Thanks Mike. I have a replacement in hand.

Sixto
95 S420
87 300SDL

Yep, just pop the lenses off, remove the two main bulbs, and remove the screws beneath them.

Got new aspirator in place. The replacement has the same part number as and an MB logo like the old one but the new one has a rectangular case while the old one has an eliptical case. I should have taken pictures but I was too concerned with...

... the trim piece between the dome light cluster and the rear view mirror. It fell off when I pulled the dome light cluster and the tabs which keep that trim piece in place are gone. Sigh.

Ken, any idea what those swing down levers are between the dome light lenses and reading light lenses?

Thanks,
Sixto
95 S420
87 300SDL

Sixto...
Not sure what you mean by "swing down levers".. don't recall any levers...

You can see a gray lever hanging down between the reading light and the dome light sections. There's a similar lever on the driver's side.

Maybe pulling the lever releases the diffuser but it seems more difficult to hook and pull the lever than the diffuser itself.

BTW, does your 140 dome light fade to darkness or just go off after a few seconds of closing the last door? Mine just goes off. I'm not sure why I think it should fade.

Sixto
95 S420
87 300SDL

Well, MB clearly made a design change with the '96 year.
Your lens is in two pieces... one toward the windshield that surrounds the switch and another that covers the main bulb.
My W140 has the lens all in one piece. Checked a '98 today and its one piece also.
When I pop the lens off, I can see where the grey plastic housing is molded to have a lever there, but there isn't any...
So, they obviously got rid of the levers (whatever they were supposed to do) and went to a one piece lens.

My dome light stays on for 20-30 seconds and then just shuts off... no fade.