My fans in the center of the car blow cold air constantly but the fans at each side of the car blow hot air constantly! It doesnt matter what i have the dials in the car set at they only blow out Cold in the middle and hot at the side!

If anyone has any answers i would appreciate it.

 

Since you are gettting cold air inside the vehicle, that pretty much rules out anything but a "diverter" switch that directs the air to any particular duct or area of the inside of your car. It could be the actual mechanism that diverts the air, but I would be sure to check what you turn to direct the air to those side vents first.

 

You may have a vacuum leak.
Look at this link.
http://www.club202.com/forums/showth...ht=vacuum+leak

My car is in the shop right now for that problem. Likely to be an expensive fix as it requires removing the entire dashboard. There's a link in the thread I sent you that will give you step-by-step instructions for diagnosis and repair.

Good Luck!

 

I might as well just break and send it to the shop because ive tried everything and cant seem to find the problem. im sure its something small... but will pay big.

 

Well, before you lose hope try doing a small fix before you go and try to pay for a big one. Do a search for "duovalve" in this and other MB forums. The duovalve controls temperature switching. It sits under the plastic cover on the passenger side of the engine compartment and looks like 2 "C" batteries stuck together. There are some rubber seals in it that eventually degrade and cause the valves inside to stick.

You can get the part online for $180 or so and when you look at it, you'll see its pretty easy to get out. There are two hoses that have coolant in them, and you should take the cap off of the coolant resevoir to relieve pressure in the system before you remove the hoses. OH, AND make sure you do the replacement when the car is COLD. You don't want hot coolant spraying all over your arm.

A shop should do the vacuum leak thing for around $750, and replace the duovalve for around $500. If you can do it for $200, you save a lot of money.

 

And if you can't find the duovalve, you might have a monovalve. Keep looking.

 

jgustin,

I got the "duovalve" out. there are 3 ports on the thing and i blew in the front one, to see if air would pass thew it. When I did so it seemed fine for a second ,air went threw it and out the two back ports. The flaps in it blocked the air from going further and when you blow in it the other way it stays obsteructed. is this normal or does it seem that i need to replace it and if so can i still run my car without it on ill just keep the ac off. thanks

 

called the dealership and the part would cost 362.81 plus installation??? looked on line and i can get it for 197.00.

 

Air action seems to be about what I would expect based on how the part is put together.
I wouldn't drive without it on simply because I know that coolant flows through that part and I'm not sure I would not want coolant flowing in a circulatory pattern. Price seems about right for the part online. But seeing as how you got it out so easily, you might as well install it yourself and save the money.

I took mine out and took it apart to see if there was anything obvious wrong with it. Other than the seals being rotten, I couldn't pinpoint anything else but that might be enough to cause a malfunction and require replacement.

http://mbclub.co.uk/forums/showthread.php?t=26888

That link goes to a write-up on cleaning the duovalve on a W210. Looked exactly the same as mine. Knowing what I know now, though, I think I wouldn't bother. Just replace the part and install it yourself.