PeachParts Mercedes-Benz Forum - View Single Post - Question for 190E owners who've had max heat/heater valve problem

euronatura · #3 06-07-2004, 05:52 PM

mikeohart:

Since no one elsa has chimed in I will give you my personal experience. Note, I am not an expert and some of the diagnosis I had done with a professional. Furthermore, my car is an 88´190e with AC.

Now you are having problems with you system is similar to what I was having some time ago. First off, are you sure that you changed the correct heater valve? On my car the heater valve actuator is more like @$100.00 part (if I recall correctly).

Now these heating/cooling systems are worked with actuators that are vacuum controlled. On my car, there are 3 behind the dash and then the heater control valve somewhere behind or in front of the firewall. On my car I was having problems directing the air flow and the air mixture. The diagnosis was that one or two of the actuators behind the dash were bad. To get to these you need to take out the dash on these cars. To check them, there is a central vacuum control unit behind the dash to the right of the glove box. To get to this, if I recall, you need to take out the glove box and from there you can connect your mighty vac to check vacuum on the different actuators.

Also, on my car, the Klima relay was bad which was also causing problems. Not too sure of your car has a klima relay but on mine it is located behind the batery next to the OVP fuse.

lastly, another source for the problem on your car can be the push button control that is in the dash. I have heard that you can pull these out and resolder the joints and it should give you a little more life out of them. Same thing with the Klima relay.

Hope that this helps you somewhat. If you do a search on ac - klima relay - actuators you may get more information.

Iggy