[W126 Coupe] 1985 500 SeC

[Axel Wulff]

Rick,

Did you try changing the Monovalve?

It sits above the auxiliary water pump you mentioned you have checked out.

Otherwise, I'd suspect the fan that pulls air in from the compartment may be 
malfunctioning. The inlet for this fan is next to the rearview mirror. Put 
the heater to defrost and with a light piece of foil or paper, try to see if 
there is any suctions there.

If this fan is malfunctioning, the ACC unit will measure the temp of the air 
in the dash and will "think" the car is nice and toasty.



Regards,
Axel J. Wulff
610-731-5453 Cellular
610-572-4611 Home






>From: WRick11499 at aol.com

>Reply-To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>

>To: mbcoupes at mbcoupes.com

>Subject: [W126 Coupe] 1985  500 SeC

>Date: Sun, 18 Feb 2007 13:41:24 EST

>

>Its cold here in MD. and my heater is acting crazy. Some times works and

>sometimes not.I bought a rebuilt  climite control unit and it does the  

>same

>thing.Some times the defroster blows hot and the center vents blows cold  

>and

>sometimes every thing works alright but most of the time   all  blow 

>cold.The

>small pump on the firewall seems to be working plus I bought  a newOverload

>relay.If I disconect  a battery cable and then replace  it, itseems to be 

>O.K. till

>I turn the key off, so I think it must be  electrical, are there other 

>relays

>that I should check and where are they  located in the fuse box, has anyone

>else had a problem like this.Thanks for  any help    Rick




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