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 03-20-2002, 09:35 AM
Registered User
Join Date: Feb 2002
Location: Kingston NY
Posts: 114
190e climate contral test

Is there a way to test the actual climate control unit? I cannot get the heat to turn off in my 1985 190e no matter what I do. Does not matter what temperature I set it at or which of the buttons is pushed. Nothing but heat. Before I spring for a new climate control unit I would like to perform some tests on it. Looks like it probably could be tested with an VOM, but I do not know for sure. Thanks for any help.
Reply With Quote
Old 03-20-2002, 12:00 PM
Registered User
Join Date: Aug 2001
Location: Santa Maria, CA
Posts: 49
Climate control system

There are a lot of tests that can be made--a whole book full of them! I know very little about the CC system, but I do have the Model 201 Tempmatic CC Service Manual from Mercedes.

Sounds like the hot water is continually flowing into the CC heating element. I would first check the heater valve, which is a vacuum operated valve located below the air intake grill at the front of the windshield--to the left of the Windshield Wiper motor as you face the front of the car. This valve controls the flow of hot coolant into the heater core. According to the manual, the valve is CLOSED when vacuum is applied, and OPENED when vacuum is absent. Could be a leaky hose, bad valve or bad vacuum switch, but at least you can start at the valve. If you have a vacuum gauge, you can connect it to the hose to see if any vacuum is present when the heater is supposed to be off.

The switchover valves are located below the instrument panel on the passenger's side of the car, it appears from the picture.

Good luck, it is a complicated system. I would at least make this test before you replace the control unit. You should also check the auxilliary coolant pump--on my car it is on the left side of the engine compartment across from the exhaust headers. It is supposed to pump coolant from the heater core when the heater is on. Check to see that it is off when heat is supposed to be off. If it pumps all the time, the control unit could be bad.

Try to find a copy of the Tempmatic Climate Control Service Manual if you need to really get into the system.

Good luck

Tom Elerding
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

Similar Threads
Thread Thread Starter Forum Replies Last Post
190E: Climate control - The trick to removing it? haasman Tech Help 8 04-11-2011 12:36 PM
85 190E "Euro Version" climate control 100% dead! 2 8 Tech Help 1 10-08-2004 01:29 AM
cylinder leak test - 190E stangd Tech Help 1 09-06-2003 10:43 PM
190E climate control problem ibdegen Tech Help 3 08-16-2002 05:27 PM
My 93 190e 2.6 Failed the emission test, tech help ronald_m Tech Help 13 04-07-2001 10:37 PM

All times are GMT -4. The time now is 09:01 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