Why this green wire?
 

So, when I found a green wire coiled up under the passenger side of the dash in my car that was plugged in to a vacuum line for no apparent reason, I figured it was an idiot PO's work. I may be wrong, as it turns out.

At the salvage yard the other day, I found another '77 300D exactly like mine in every way except for having a sunroof. The dash had been pulled, and this is what I saw.

http://i7.photobucket.com/albums/y27...isthiswire.jpg

The red arrows point to the wire and the vacuum line it is stuck in to. What the heck is that there for? One end is just cut off and coiled up. The other end is plugged in to a vacuum line behind the climate control panel. Why? Both my car and the salvage yard car have this same ridiculous wire! My brain is going to explode!

Seriously, folks... Anyone know why this exists?

I see why your brain is exploding. Mine is quite perplexed too???? Where does the vacuum line go to?

Not positive, but I believe it hits a tee fitting that looks as though it's connected to one of the tiny vacuum pods directly behind the climate control. I don't recall what those do, as I haven't really dug in to the interior vacuum system, yet.

It is one of the cabin vents. I too asked the same question. Apparently the coil of wire leaks air. After 20years not nearly as much as the joint where it connects. I removed this on mine. The problem is that in doing so I ended up popping one of the bigger vac pods shortly there after. Dont mess with it. It is a "feature" of the type 2 climate control.

May not be vaccume line at all. might be a light pipe for something.

To my knowledge, a '77 has type 1 ACC. Do you mean to tell me that Mercedes-Benz, in all their engineering glory, used a freakin' coil of wire to allow a slight vacuum leak?

My brain still hurts.

I saw this on my car and thought it was quite obvious what it was for. It is a catheter for use on long road trips. Mine works really well. :D

Same function as the PRT in airplanes?


AKA, the Pilot Releif Tube.....

It is a "leak point"... as designed by CHRYSLER that MB bought the system off of. I'm sure Chrysler laughed all the way to the bank on that one (its so bad we won't use it, but we convinced the Germans to buy it!! :deal:)

http://www.duricy.com/~imperialist/AutoTemp/autotemp.html
http://www.imperialclub.com/Repair/Lit/Master/244/index.htm

There's just some things those of us living on the ground don't need/want to know.....

So is that what the occasional odd feeling of drizzle is on a nice sunny day?

Ok, that answers my question as well....

Yes, that is the couse for the drizzle on sunny days.... lol......:P


:wacky::D

My old '77 parts car had the exact same coiled green wire. I assumed it was previous owner's hack job. Quite surprising to find out otherwise......:freak:

I'm aware that Chrysler designed the POS ACC (Automatic Climate Catastrophe) system. What I still don't understand is why Mercedes used it. It's a mostly ingenious system that for the most part simply suffers from the utilization of poor materials. This wire, on the other hand, is just shear stupidity. A chunk of wire for a vacuum bleed? Holy crap. If I ever find the guy that made the decision to use this ridiculous green wire instead of a proper vacuum bleed valve, I won't care how old he is. I'm kickin' him right in the junk. Maybe twice for good measure.

LOL! I am not condoning it but please do get a video of it if you do.