Home | Contact Us | FAQ | Search & Site Map | Link to Us
Sign In | Join | Other 45 Sites in Network
HomeAnnouncements
Discussion Groups
By Brand
BMWChevroletDodgeFordGMHondaLexusMercedes-BenzNissanPeugeotToyotaVolkswagenOther Brands
By Topic
4x4 CarsRVsDrivingMaintenance & RepairCar AudioCollectible Cars
Country Specific
Australian ForumsUK Forums
ArticlesAuto InsuranceBuyingCars & TechnologyMaintenanceMiscellaneousSafety
DMV Resources
Related Topics
MotorcyclesBoatsMore Topics ...

Car Forum / Mercedes-Benz Cars / June 2005

Tip: Looking for answers? Try searching our database.

Heater always on

Thread view: 
Enable EMail Alerts  Start New Thread
Thread rating: 
Ben - 05 May 2005 04:19 GMT
The heater in my 91 300CE seems to always be blowing.  The
climate controls are non-functional and have no effect on
the heat coming out of the side and defrost vents.  What
could be causing this?
Tiger - 05 May 2005 05:20 GMT
Loose vacuum hose is primary culprit... check for loose vacuum hose in
engine compartment.
Ben - 10 May 2005 06:21 GMT
I looked and nothing seems to be loose.  Could there be
another likely cause?

> Loose vacuum hose is primary culprit... check for loose
> vacuum hose in engine compartment.
Tiger - 10 May 2005 17:08 GMT
It may not seem obvious... but look on your firewall area... there should be
two yellow checkvalves... one in and two out... check those connections...
make sure the nipples are not broken.

Other thing to check is on the side where there is only one... pull it out
and make sure you got good vacuum.
Ben - 13 May 2005 15:36 GMT
I messed around with the checkvalves and tubes a bit and
voila, the climate controls started working again.  They
probably still need replacing soon though.  Thanks!
Tiger - 14 May 2005 18:42 GMT
Replace those checkvalves... very very simple job... Welcome!
Ernie Sparks - 24 May 2005 21:10 GMT
> Replace those checkvalves... very very simple job... Welcome!

Although it's a simple job my local MB stealer quoted me $34 apiece for
those little pieces of plastic. Any idea where these can be obtained for a
realistic price?
Tiger - 25 May 2005 14:28 GMT
Try any online part store... I remembered paying $10 each... been a while
though.
Ben - 30 May 2005 03:13 GMT
I replaced one of the checkvalves (the one with two
connections) but it hasn't fixed the problem.  Should I
replace the other one?  From what I've read the the one I
replaced is connected to the line that controls the heater.
Ernie Sparks - 04 Jun 2005 01:39 GMT
What type of vehicle are we talking about here?

> I replaced one of the checkvalves (the one with two
> connections) but it hasn't fixed the problem.  Should I
> replace the other one?  From what I've read the the one I
> replaced is connected to the line that controls the heater.
Ben - 13 Jun 2005 21:06 GMT
91 300CE

> What type of vehicle are we talking about here?
>
[quoted text clipped - 3 lines]
>> replaced is connected to the line that controls the
>> heater.
 
Sign In
Join
My Latest Posts
My Monitored Threads
My Blog
My Photo Gallery
My Profile
My Homepage

Start New Thread
Enable EMail Alerts
Rate this Thread



©2008 Advenet LLC   Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.