I FINALLY fixed the hvac pods on my W124. NEVER AGAIN! I finally have air blowing out of my center vents. Yay!

Last night it was 51 degrees outside. I had the climate control set to Economy with the heat set for 72 degrees. The side vents were blowing out hot air but the center vents only blew out cool air. MAYBE 20 minutes the center vents began to blow out VERY SLIGHTLY lukewarm air at best. Why is that?

jeff

When in Economy, the center vents should only be open when the pushbutton unit determines that the inside temp is warm enough to bring in outside air. It will not be heated. When in heating mode, the center vents should close and warm air come out the side vents, and depending on the setpoint, floor vents and defrost nozzle.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

So do I have something set wrong? Because cool air is coming in. I don't know if it's necessarily outside air, or maybe it was just the cool cabin air that hadn't been warmed up yet. Either way, it was blowing cool air for a long time.

Yes

The center vents should close when in heating mode.

Center vents are only open in cooling mode and they can only blow cold air.

I think it's possible to close them manually but i'm not sure about the w124

Maybe so, maybe no. Turn the temp wheel up warmer, preferably into the red zone. The center vents should close and hot air should come out the side vents, footwells, and defrost nozzle. If the climate control unit doesn't think it's in heating mode, the center vents will be open. In EC mode it is just un-conditioned outside air.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

No, nothing's making a difference. My floor heat isn't working either no matter what setting it's in; economy, bi-level, etc.

You should not have any air blowing from the center vents when heating is called for, only the side, foot and defrost should blow

I think your center vent linkage is binding or the flaps foam seals are bad.