Author Topic: ACC is functional!  (Read 11907 times)

1980sdga

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Re: ACC is functional!
« Reply #15 on: 25 May 2011, 04:18 PM »
I think that's what I'll do. The system works fine when I solder the joints back and it then it fails once everything has warmed up. My servo may be sticking when the engine is up to temp and hot water is at the valve.  It seems to work fine once I straighten it out and test in the garage but once I take it on the road it craps out when I give it input from the thumbwheel.

Also with UT, if they stop supporting the product for what ever reason then you're STUCK! 
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

Hemersam

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Re: ACC is functional!
« Reply #16 on: 25 May 2011, 04:55 PM »
sdga: if you wish, you can email me to find a potential seller (in my area) of "real" R12 refrigerant.
dr.fr.j@hotmail.com
Hemersam

1980sdga

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Re: ACC is functional!
« Reply #17 on: 25 May 2011, 06:05 PM »
sdga: if you wish, you can email me to find a potential seller (in my area) of "real" R12 refrigerant.
dr.fr.j@hotmail.com
Hemersam


Mine has been converted to 134a but I don't know if that was just a valve change and evacuation/recharge  ???  It has been working pretty well the past few days, especially on the freeway but it could use just a tiny bit more cooling power.  Was an expansion valve usually part of a "pro" conversion circa 2000 ?
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

Hemersam

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Re: ACC is functional!
« Reply #18 on: 25 May 2011, 07:42 PM »
As far as I know, the expansion valve was replaced by some, but not by all (most, I think).
Hemersam

Hemersam

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Re: ACC is functional!
« Reply #19 on: 26 May 2011, 05:04 AM »
Let me pose a "theory" for those on the forum who know 1,000% more about these things than do I. Since the a/c system on a 116 always takes in some outside air (20%, I think), the faster you drive, the more of that air is entering your a/c system, thus making it harder to get maximum cooling inside the car (isn't that the point of re-circulated a/c?). I find that my a/c cools a little better at 35 mph than at 70 mph. My theory seems to make sense, but I don't know if it's true or not. I am open to enlightenment.
Hemersam
Dallas, Texas, USA

BWalker82

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Re: ACC is functional!
« Reply #20 on: 26 May 2011, 05:14 AM »
Let me pose a "theory" for those on the forum who know 1,000% more about these things than do I. Since the a/c system on a 116 always takes in some outside air (20%, I think), the faster you drive, the more of that air is entering your a/c system, thus making it harder to get maximum cooling inside the car (isn't that the point of re-circulated a/c?). I find that my a/c cools a little better at 35 mph than at 70 mph. My theory seems to make sense, but I don't know if it's true or not. I am open to enlightenment.
Hemersam
Dallas, Texas, USA

I figured the same thing.  My blower does not seem to work.  However, when I'm at speed on the motorway, plenty of air comes thru the vents (albeit always hot air).  It was nice in the past few weeks when it was cooler here in GA, but now, summer's coming on. 
-BW

1980sdga

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Re: ACC is functional!
« Reply #21 on: 26 May 2011, 08:09 AM »
The manual says that the fresh air has 3 positions:

"OFF" is no fresh air input
All operating stages are 100% fresh air except "Max Cooling" which is 20% fresh air and 80% recirculated air.  I've been running my AC quite a bit with the fresh air pod unhooked (It's leaking) and I'm not sure what position I left it stuck in  ::)

Joe got me a new fresh air pot so it'll be neat to see how it functions!

Hemersam, does your blower work while on "Defrost"?  If it doesn't then I'd start with fuses, blower motor and the blower relay.  The car is engineered so that the defrost will still work if the rest of the system fails.  If the blower works on defrost I'd move on to other areas.
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

jbrasile

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Re: ACC is functional!
« Reply #22 on: 26 May 2011, 08:32 AM »
Jon, with the fresh air pod unhooked you should have no fresh air coming in, it would be as if the system was OFF

Tks,

Joe

1980sdga

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Re: ACC is functional!
« Reply #23 on: 26 May 2011, 09:28 AM »
Jon, with the fresh air pod unhooked you should have no fresh air coming in, it would be as if the system was OFF

Tks,

Joe

I've been running on "Hi Cool" a lot the past few days so having no incoming fresh air, along with plugged drains, is probably adding to my "swampyness".  The designers obviously wanted some fresh air through the system when on "Hi". 

I'm pretty confident we can get this issue resolved  ;D
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

Hemersam

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Re: ACC is functional!
« Reply #24 on: 26 May 2011, 11:16 AM »
The "defrost" on my a/c works as designed, as do all other settings. I wonder if you were to block the fresh air intake, would the a/c continue to cool and would it then be working more-or-less like a newer car set on "recirculating air." Anyone know?
Hemersam

1980sdga

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Re: ACC is functional!
« Reply #25 on: 26 May 2011, 11:54 AM »
The "defrost" on my a/c works as designed, as do all other settings. I wonder if you were to block the fresh air intake, would the a/c continue to cool and would it then be working more-or-less like a newer car set on "recirculating air." Anyone know?
Hemersam

I was thinking along those lines as well but I'm shooting for factory operation  :P  You should try fixing your fresh air element in place set to no outside air.

I have one side of the element leaking on the element in my car.  I can't get ANY actuation in one direction and NO vacuum would build up when tested.  The other side holds air...

Here's the element I got from Joe:



I still haven't really looked to see what and how it actuates  ::)  It's near the pink actuator that also controls fresh air.  I think maybe it takes the 2 valves to accomplish the on/off/20-80.  Still haven't dug in to see how  :-\  It's not necessary for this part of the system to be functioning for the rest of the ACC to work so I just bypassed it for the moment.

I'm also having some humidity issues which are mostly related to plugged drains (I believe) but couldn't it also cause some humidity problems (Or something else) with having 100% recirculated air ?  Maybe new cars actually have some fresh air taken in when on recirc?  Just thinking aloud...

Everything I know (Or think I know  ;D) about AC systems has mostly been picked up in the last few months so keep that in mind  ;D
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

jbrasile

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Re: ACC is functional!
« Reply #26 on: 26 May 2011, 12:54 PM »
If the fresh air actuator is completely bypassed you will have 100% recirculation all the time without the possibility of getting any fresh air under any circumstance. I believe 1980sdga is right in pointing out that the pink actuator that works in conjunction with the blue/white one is what controls  the 80/20 split when maximum cooling is required. It would be interesting to see if it is possible to somehow have 100% recirc under maximum cooling and 100% fresh air under normal operation, maybe bypassing the pink element would achieve that.

I have my system setup to recirc 100% of the time and don't have a humidity build up issue, and that's in Sao Paulo Brazil where humidity can get up to 85-90% in the summer. I really think if the drains are ok even with 100% recirc there should be no fogging of the windows.

Tks,

Joe

1980sdga

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Re: ACC is functional!
« Reply #27 on: 26 May 2011, 01:43 PM »
How is yours set up for 100% recirc? Is the element just not hooked up?

I'm going to try to figure it out when I install the new element but I need the support bearing on the driveshaft  :-\  I found that while cleaning out the drains  ::)

Not really surprising though. I consider it a wear item.
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's

jbrasile

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Re: ACC is functional!
« Reply #28 on: 26 May 2011, 02:11 PM »
Yes, I bypassed the element, the vacuum hoses are plugged.

003 981 23 25 - driveshaft support bearing - $26.55 original MB

Tks,

Joe

1980sdga

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Re: ACC is functional!
« Reply #29 on: 26 May 2011, 03:02 PM »
Hey Joe, does that bearing include the rubber around it?  I need to look and see exactly what I need.
Jon


Little by little I have grown fond of the infamous Auto Temp II we have in our 116's