The evil servo is not so evil, but Norm is still AC less!
 

Hey guys,

As you may remember, Tyler posted that Norm had a bad climate control servo and thus ordered a new one to be replaced and installed.

Well I had that done over the last few days, but to no avail. I took Norm in last Thursday, and just got him back today. My mechanic told me that the aux. water pump was ceased, so he replaced it. He installed the new rebuilt servo, and nothing happened.

Now here is where it gets fishy... My mechanic said that the next thing to replace is the "de-ice switch" which would cost about $620. Obviously I told him to hold off on that. But what exactly is a "de-ice" switch? I hope it's not just the defrost switch on my AC cluster, but no way should that be so expensive!

Anyone know what this thing is? And if this is not the problem, anyone know what else might need to be replaced to get the ACCII working? It's a little baffling really!

Thanks for the help guys!

I have no idea what a de-ice switch is. What was the original problem?

^Same here, that's why I'm a bit baffled...

The original problem was thought to be the climate control servo, that it was dead, so Tyler sent me one with Norm when I bought him. While that was being installed, it was found that the auxiliary water pump had ceased, so that was also replaced, but the system still does not work. My mechanic then told me that the de-ice switch was bad, so I'll have to have that replaced.

I'm just a little confused, thats all...

I've never heard of a de-ice switch...
Is the mechanic German?
Maybe he means the monovalve? That can be repaired easily. Does it blow at all, or does it just not blow cold? Do you have heat in high and low settings as well as defrost?

I know you thought the servo was bad. What was it doing to make you think it was bad?

He's probably talking about the ACC amplifier. When the AUX water pump fries, it takes out the amp with it, or vise-versa. You can take off the glove box inside by taking off the small clips inside the glove box. It's a small circuit board in a black plastic housing. If it's fried, the ACC won't work. You can check if it's toast by looking for burned contacts on it, IIRC rebuilt ones are about $100, you can try to fix it by re-soldering all the joints.

To remove the ACC amp, remove the glove box inside by prying the clips off, take off the amp by loosening 2 screws and unplugging a harness. Also you can test the amp with a multimeter, seach for the exact procedure. New from MB the board probably cost $500 or something rediculous, but rebuilts are good.

I have nothing, it pretty much just blows air and thats it. No cold air, no heat, just air.

That might be what he is referring to, that piece I have heard of. Neither one of them are German, but I could see him calling it that.

Tyler's thread was deleted, but I remember him telling me that heat and cool air worked sporadically, and mostly not at all. Finally it just stopped working all together. If he sees this I'm sure he'll explain, I read the thread but don't remember a ton about it.

This actually sounds familiar, because he told me he would have to get behind the glovebox to fix it. I'll have to open up the glovebox when I get a chance and check it out. This might be exactly what he is talking about. From fastlane, $230, not too bad considering what I could pay...

Colin doesn't have a mono-valve.

Check you local junkyards for a climate control amp. That sounds like your problem.

Yup, my thread was deleted because I was posting competitors to fastlane for a servo rebuild.:(

From what Colin told me over the phone, I interpreted it as the guy doing electrical tests of the CCU itself, and the de-ice or perhaps defrost was causing the system to go nuts.

Perhaps he thinks the climate control is fried, and $600.00 retail for a rebuild sounds about right. Of course, you can find good ones for less than half that price.

I was hoping to get the part number so we know exactly what they're talking about.

Soon to be good used Servo for sale in the parts section...:o Oh well, it was a good thing to replace anyway.

^^Oops, forgot to mention that Norm is a 1980 300TD, so there is no confusion again :D

Will do, but sadly there are no really "good" junkyards around here with any 123's sitting in them. I will take a look though!

Thanks for the help guys!

^Yeah I asked about a part number and he said he was going to email it to me tomorrow morning. I picked Norm up on his way out of the shop, so I wasn't going to make him unlock it for me again. I'll post it when I get it in the morning...

Sorry about that!

I have a line of text listing my cars so the dial up folks don't get cranky. Someday they'll enter the 21st century.

George Murphy sells rebuilt servos and amplifiers, and vacuum diaphragms. IIRC, a rebuilt amp from him is around $100.

Used working ones are $30 shipped on ebay. Search "Mercedes climate amplifier" to find them.

http://img329.imageshack.us/img329/7...6123107he7.jpg

They look like this.

I had to deal with fixing the servo climate control system, and it completely works (it's nice!) so if you need help feel free to ask me. There is a learning curve on ACC work, particularly the older version.

That servo amp is very likely your problem. I've never pulled one out of a car at the yards that wasn't fried. Most of them you can see the burned area!! :eek:
I hope your mechanic fused your aux water pump. If not you need to do that or have it done.

Hmm, I'll have to check that out. If I can get one for $30 shipped, that's awesome! I need to save any penny that I can with Norm! I'll look in to that, thanks!

Yeah he fused it. This is one of the many things he told me about what he did over the phone. See, I can't retain everything that he says, because if I could I could probably rebuild Norm from the ground up! That's why some times I sort of sound "fishy" when talking about what he has done.

He's really thorough and really a great mechanic, but he really likes to replace EVERYTHING possible. I guess if your pocket is deep enough, that's great, but mine isn't really. He really knows what he is doing, I just have a hard time keeping track of all of it! He also uses terms and part names (like the deice switch) that I have never ever heard of, so that throws me for a loop as well.

Oh well, crisis averted I suppose. Thanks for the help!