Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 11-15-2002, 01:52 PM
Posts: n/a
Heat on 420SEL

I bought a 1987 420SEL in April. All summer the air conditioning worked just fine (After a recharge). Now that it is getting cold here (MI) I am trying to get used to the heating system and I don't know if this is how the car is supposed to work. When I push in the center button on climate control and set temperature to around 22 (C) after a couple of minutes the hot air mostly blows out of the defrost, never down by my feet, with some hot coming out the dash vents. This is really annoying to have all the hot air go up the windshield and directly into my face all the time. I am constantly running the heat for a few minutes then having to shut it off as I can't take the hot air directly in the face. I am sorry to report that the MB dealership right down the street from my business are complete morons (at least the advisor guys that you talk to when you go in) and can't even explain if this is operating correctly or not. I just want the hot air to blow from the dash vents or below when I turn on heat and blow from the defrost vents when i press defrost. Anybody know if there is something wrong or if this is what I have to live with during winter months?

Lee Byrum
Reply With Quote
Old 11-15-2002, 05:02 PM
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
The air flow is controled by vacuum actuators that move flaps in the heater box.
Sounds like your car isn't GETTING the vacuum to switch the actuators as needed to open & close the vents.
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator
Reply With Quote
Old 11-15-2002, 05:13 PM
dpetryk's Avatar
Electrons can do anything
Join Date: Sep 2001
Location: Houston, Texas
Posts: 1,071
The actuator diaphrams are probably rotted out. They usually are at that age. Replacement is a difficult job for a few of them. I have also seen the vacuum switch cause these problems as well.
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 11:07 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page