Parts Catalog Accessories Catalog Tech Info Tech Forums
  Search our site:    
 Cart  | Project List | Order Status | Help    

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

LinkBack Thread Tools Display Modes
Old 04-30-2003, 01:35 AM
Registered User
Join Date: Mar 2003
Posts: 18
Another 300E Air conditioner Benzmac?

Hi everybody, I talked to Phil when ordering more parts from partshop and he reccomended I e mail Donnie. I'm sure others are having similar problems so here it goes.
First my A/C has been working intermittently for a couple years.......i've lived with it.
Now its not working at all.
I had my A/C buddy put in some freon which he did, so I know my system is full.
My compressor is running and the engine is underload with switch turned on.
Still no cold
Then a week ago the A/C mysteriously starts working........I say cool (get the pun?).
Unfortunatly its not working once again....same thing compressor is full of freon, clutch engaging, underload but no cold.
What can the problem be?
Phil said possibly the drier, could that be it?
the system has not been opened to the outside enviorment although it does have 134 in it.
It dosent seem to be taking heat off the heating side of the system (is that possible) so it appear that it might be something electrictial in nature.
Benzmac and all involved thanks in advance for the assistance
Reply With Quote
Old 04-30-2003, 01:42 AM
haasman's Avatar
Registered User
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,096

Your car is an '89 300E?

'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
Old 04-30-2003, 01:45 AM
Registered User
Join Date: Mar 2003
Posts: 18
Yes (thanks) 89 300E no text

Reply With Quote
Old 04-30-2003, 05:09 AM
J.HIDALGO's Avatar
Registered User
Join Date: Jul 1999
Location: Jax, FL
Posts: 1,785
Is it blowing hot air or NO air?

It could be many things but, if it is blowing hot air, it could be the monovalve. YOu are not too clear in your post...
"It dosent seem to be taking heat off the heating side of the system (is that possible) so it appear that it might be something electrictial in nature."
Need some more info!
'86 300E
Reply With Quote
Old 04-30-2003, 06:33 AM
Posts: n/a
To properly diagnose A/C problems it is necessary to answer Mr. Hidalgos question PLUS we need to know high and low side pressure and vent temperature.

On the 300E the heater valve typically fails in a normally off mode. If it is flowing when it shouldn't the problem is most likely the pushbutton control unit, but it should be checked before replacing any parts. You can simply feel of the hose before and after the heater valve. If both are hot the heater valve is flowing hot coolant to the heater core, thus offsetting the refrigerated air from the evaporator.

Get pressure readings, vent temp and give a complete description of what is happening with the blower and maybe we can help further.

Additionally on this particular car, you need to see that air is being drawn into the small grille near the rear view mirror. There is a small fan motor behind the glove box that draws air through that grill, through a tube and to the temp. sensor. If that is not drawing air, all sorts of crazy things will happen.

Good luck,
Reply With Quote
Old 05-08-2003, 12:22 AM
They call me Darth Speed
Join Date: Apr 2002
Location: Hawaii
Posts: 327
I have a similar problem but I know the blower motor is not working. When Driving you can feel the cold air from the vents.

HOW DO YOU TEST THIS EASILY? Is there any simple bypass or do you have to take apart the whole dash?

87 300E
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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 10:07 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page