w124 climate control

[dablk1]

Hello all. This particular problem is occuring in a 1993 300E. It's a friends car and I'm trying to help him out. First, the blower motor itself is fine. I checked it myself in and out of the car. Now the big issue is the fact that no air at all is coming out of any of the vents when any button is pushed on the CCU. He said that it use to work just fine and suddenly it just stopped. I was leaning towards the pods when he initially told me about it, but after reading quite a few threads it seemed unusual for all of the pods to go bad at the same time. Could this be caused by a faulty CCU? Another reason I was thinking that it might be a vacuum issue is the fact that his door locks are inoperable. They key won't turn the drivers door lock in either direction. Any suggestions??

THe door locks operate on an electric vacuum pump under the back seat. I've never thought about it before, but I don't think that the Climate Control system uses this same vac source.

You can check the pods rather easily by simply removing the glove box liner and looking below and to the right of the opening. There you will find a manifold called the switchover valve. Remove the hoses one at a time and check them with an auxialliary vac source. If there are any leaking, make sure you plan on replacing them all because it is a fifteen hour job to gain access to them.

Hope this helps.

[dablk1]

Thanks, I'll check them out. The switchover valve on mine I believe is to the left as I look into the glove compartment.

Yes, I said right, but meant left. This is a day when the two brain cells that I have left were not aligned. A dyslexic attack I suppose.

[jcyuhn]

Larry is right - the door locks and the climate pods are completely separate. The climate pods are operated by engine vacuum, controlled by the CCU and the valve behind the passenger airbag. (I think the airbag was standard in '93 in the US - replaces the glovebox.)

It sounds like the fan is not running. The outside dash vents are not controlled by any vacuum pod, so if the fan is running, they got air.

I would start by checking fuses. In particular, the fuse for the blower fan. If memory serves (I don't have any more functioning brain cells than Larry - see what these cars do to you!) the blower fuse is in a small, black enclosure outside the glovebox.

Also work through the fusebox, to insure the CCU itself has power.

If all the fuses check out OK, I would be looking at the blower regulator next. You should be able to find instructions on how to diagnose it using the search feature.

Cheers,

- JimY

[ss327iroc]

I have the exact problem with my 91 300d 2.5

I was in the car when this happend, fan motor fine (no noise) that I changed from auto to high, and no fan and none of the buttons worked. Later I restarted the car and everything worked fine. the other buttons work fine the ac comp comes on and off. Then nothing, the fan will not work at all with any of the 3 buttons. Everything else works fine. Where is the blower regulator???

[ss327iroc]

Just fixed mine by replacing the fuse. It is in front of the brake master cyl. 1"x2" BLACK BOX. fuse had a small crack in it. Try that.

[cleavster]

Same here! I changed the fuse due to a hairline crack. To my recollection, it's a 30amp fuse.

[macdrone]

Yep strip fuse is common. Its on the drivers side strut mount in a tootsie roll side case.

For the person who asked where the regulator is its under the blower moter which you have to pull the wiper assembley to get to.

[babymog]

Strip fuse is also available from VW/Audi dealer.