My ACC is annoying, problematic, and hard to use (rant).

My Mercedes has ultimate 80's luxury automatic climate control. I hate it.

To the left is the temp wheel, the center buttons do "stuff," and the buttons to the right are for the blower. Blower controls are "some," "auto," and "all." Urg. What was wrong with 1-2-3-4. I find no discernible difference between any of the blower buttons. They all either set the blower to "meh," "OK, I'll work for a second, then berkeley you," or "none."

My main issues: I have no control over which ducts the air come from. URRRG vacuum servos. Also, whenever the ACC is on, strange gurgling noises comes from the engine bay and the idle drops. I don't think that is supposed to happen.

I've got half a mind to hack in a Volvo blower control knob and some manual cable operated knobs from a 65 Ford.

80's ACC sucks donkey balls in every version I've ever encountered. My 03 xc90 has automatic, but its completely over rideable too.

I don't want to say I told you so, but....

Cheap fix for the vacuum servos: pull the glovebox out (its easy) and put a zip tie on the servo behind it. That will force air out of the outside dash vents, which is better than nothing.

Oh, and the middle vent control button is the one you want.

Fwiw, besides the broken servos my automatic air was great—I miss it.

This is the solution I'm thinking of (C&P from the Mercedes forum I'm on):

As anyone who has been so foolish as to ask me "what does that button do?" knows, I hate ACC and will take any chance to rant, spit, and foam at the mouth at the very mention of it. So it's going the way of the Gipper.

Here's what I want:

1. Blower level selection through a 1-2-3-4 electronic switch.

2. Mechanical valve for letting water/heat into the heater core. Perhaps just a cable operated pull knob.

3. Mechanical selection of defrost/upper vents/lower vents (hard part). I'd actually probably settle for a selection between defrost and all vents sans defrost.

Note: I'm in no way concerned about AC and will most likely delete it. I've never had AC in one of my cars and I've never missed it, I have windows.

The first two items seem like they'll be relatively easy to get working, the third I'm not sure on. The blower switch can probably be wired in from many many 80's model cars.

For the water control, I'm thinking about a simple butterfly valve. The amount of water would simply be controlled by how far one pulled out the knob/how far the butterfly opens. I'm not really sure if there would be an issue with this set up and the pressure in the coolant system.

For the 3rd component, I'm think about 2-3 butterflies in the ducting system that open/close the defrost/dash vents/floor vents individually.

This is literally the simplest/most mid 60s system I can think of that will still work (maybe). I've never modified a heater/water system in any way though, so I'm unsure.

I always thought 80s GM ac minus cadillac was the easiest to use and when in good operating condition was awesome

ryanty22 wrote: I always thought 80s GM ac minus cadillac was the easiest to use and when in good operating condition was awesome

As long as its not automatic, you are...mostly...correct. They should have had a mixed def/floor position like Ford did. The automatic one was just stupid.

I have had ACC in the past three cars I have owned.. in all three cases I overrode it

mad_machine wrote: I have had ACC in the past three cars I have owned.. in all three cases I overrode it

What was your method for doing this?

All I hear from the MB forums is "Mercedes had the best engineers ever to live. Their ACC is the best climate control system ever. Your homebrew system will never work as well." blah blah blah.

I say anything that works, works better than something that doesn't. I'm also not afraid to go berkeleying around with an $850 wrecked diesel MB.

all three are/were very easy to override. They had buttons for "econ" that would not let the air conditioner kick in and then I would either kick the heat all the way up or all the way down.

Here is a thought for you. Most European cars sold in the US are optioned way higher than in Europe. What are the chances you can get manual heating controls for that model from one of the European ebays?

it's funny that Mercedes couldn't make a good climate control system in the 80's when the setup in my 66 Lincoln was just awesome... turn the knob to whatever temp you wanted and choose where you wanted the air to blow and it did the rest.. the setup in my 94 Chrysler LHS was almost as good, but didn't blow as cold as the old Lincoln did.

the ACC in my 88 thunderbird turbo coupe is great, too. when you start it on a cold morning, and set heat to, say, 75, nothing will happen with the system until the coolant in the core gets up to temp, then it will kick the fan on, and blow heat wherever its cold, be it floor or dash. defrost is a completely separate system, and works well.

sorry about your MB pos, i'd junk it all and go the route you are.

-J0N

Seems like when I was looking at 560SLs there was a common fix for those things that "everybody" did because they all eventually went haywire. Maybe if you check across a couple of same-era Mercedes models you can find something in different forums.

My SAAB 9000 had some awesome ACC. I set it to 72 and never touched a thing on it ever. But it also was easy to override if needed.

The Insight I have also has ACC and it works good too, also easy to override if necessary. Generally though I run with no A/C unless I am on the interstate and it's over 82 degrees out. Gotta maximize the fuel consumption.