Author Topic: ACC is functional!  (Read 11905 times)

1980sdga

  • Vintage
  • ***
  • Posts: 813
  • Location: Ga. USA
ACC is functional!
« on: 22 May 2011, 01:18 AM »
Last night and this morning I put brakes on the SD and this afternoon I had to go on a 120 mile trip (60 each way). I figured it'd be a good shakedown run for the brakes and AC.

On the way up it was in the low 90's and the AC worked well. It was in the 60's for the return trip so I got to try out the heat. It worked fine and I'm EXTREMELY happy with the car right now  :D

The brakes feel good, the steering is tight, power is fine for what it is and all my interior lights/gauges are working as they should be  8)

I put cheapo shocks on it and the more I drive it the less I like them  :-\  It does OK but it has a little more "bounce" than I'd like.  If nothing else crops up I plan on getting some good OEM shocks and trying them out.

Anyway, all is well in 116 land tonight!

I'm waiting for a fresh air pod for the ACC to come in (Thanks Joe!) and the climate control will be functioning close to the way it was designed to operate.

I'll probably end up going with a GM V5 compressor for the AC if my old Delco gives me any trouble.  I think it'll be a better "fit" for the ACC system because it's a variable displacement rig instead of an "Always pumping" compressor.
Jon


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

koan

  • W116 Addict
  • ****
  • Posts: 3,314
  • Location: Melbourne
Re: ACC is functional!
« Reply #1 on: 22 May 2011, 01:58 AM »
I'll probably end up going with a GM V5 compressor for the AC if my old Delco gives me any trouble.  I think it'll be a better "fit" for the ACC system because it's a variable displacement rig instead of an "Always pumping" compressor.

I'd get some professional advice before going that way. Only advantage is a supposed increase in fuel economy and available power in micro engined cars. My wife's car has one and it's been replaced a few times.

Will a variable displacement compressor work with on/off switching from ACC?

koan
Boogity, Boogity, Boogity, Amen!

BWalker82

  • Enthusiast
  • *
  • Posts: 39
  • Location: North Atlanta, GA
Re: ACC is functional!
« Reply #2 on: 22 May 2011, 04:03 AM »
Is our system plug 'n play compatible with that?  I was unaware such a thing existed, but that's a nifty design.  It seems that the compressor would require some sort of input to decide and/or execute the amount of displacement to be used. 

Kudos on getting it all to work!  My AC compressor has no belt.  I'm guessing some one left it that way for a reason. 
-BW

jbrasile

  • W116 Addict
  • ****
  • Posts: 1,217
Re: ACC is functional!
« Reply #3 on: 22 May 2011, 08:43 AM »
1980sdga,

I would not mess with the V5 compressor. If you need to replace your R4, just get a new one, they work very well, last a long time and are not that expensive. Besides,300sd's are pretty efficient cars and fuel consumption doesn't change all that much when using the ac

Congratulations on getting the acc working properly, the vacuum pod should arrive on Monday or Tuesday.

Tks,

Joe

1980sdga

  • Vintage
  • ***
  • Posts: 813
  • Location: Ga. USA
Re: ACC is functional!
« Reply #4 on: 22 May 2011, 10:35 AM »
I have a friend who is a real AC guru. The guy's a whiz at doing AC retrofits  in his old cars and his systems are really reliable and work well.  It's nice riding in his early 60's cars with the AC blowing cold  8)  He's a DIY guy and has mostly uses junkyard parts for his systems. He's one of those super clever guys that I WISH I could be more like!

Anyway, he's NOT a fan of the R4 compressor and seems to be in love with the V5.  He's had some failures with new R4's and just generally doesn't like the radial design and the fact that it's not serviceable. He's rebuilt the V5's and says it's not difficult at all and can be done for about $20.

The main hitch with a swap would be dealing with the oil cooler lines which are bolted to the compressor bracket, plus building a bracket for the V5 that isn't a belt slinger  ::) 

It's just something I was thinking about. For now my AC is working well so I'm not fooling with it until I have too!  Even then I'm not sure if a swap to a V5 would be worth the trouble.  Just food for thought...

The V5 pump is a 5 cylinder with a "wobble plate" behind the clutch which changes the stroke of the pistons based on the high/low side pressures. This is how the variable displacement part works and my friend says it's really simple and reliable.  Seems like it would work pretty well with the ACC because the compressor is always on with the R4 system (Unless the switch is "off") and it uses the heater core to "overpower" the evaporator when heat is needed.  With the R4 the compressor just runs wide open all the time but the V5 has the ability to "back off" some when the pressure isn't needed.

All this is just advice from a person who's  worked the kinks out of systems and has decided what works for him. He flat out said that he wouldn't have worked on the ACC system for more than an hour before just starting over without the servo, sniffer and computer.

He was pretty unimpressed with the ACC system in general just because of the complexity.  I think that's what gives it a lot of it's charm though!
Jon


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

jbrasile

  • W116 Addict
  • ****
  • Posts: 1,217
Re: ACC is functional!
« Reply #5 on: 22 May 2011, 12:57 PM »
Sounds interesting 1980sdga, however, as far as I remember from my 79 300SD and my sister's 84 300CD, the R-4 should not stay on all the time, it cycles according to temp/pressure. Maybe the new R-4's are not as reliable as the old ones, that could present a problem.

Be interesting to find out what the benefits of a V-5 would be on say a 280 or 450, those cars fuel consumption do get affected by operation of the a/c, especially the 280's.

Tks,

Joe

koan

  • W116 Addict
  • ****
  • Posts: 3,314
  • Location: Melbourne
Re: ACC is functional!
« Reply #6 on: 22 May 2011, 04:22 PM »
Is our system plug 'n play compatible with that?  I was unaware such a thing existed, but that's a nifty design.  It seems that the compressor would require some sort of input to decide and/or execute the amount of displacement to be used. 

All internal to the compressor, diaphragm(s)y sense pressure and move things to control displacement

koan
Boogity, Boogity, Boogity, Amen!

1980sdga

  • Vintage
  • ***
  • Posts: 813
  • Location: Ga. USA
Re: ACC is functional!
« Reply #7 on: 22 May 2011, 05:31 PM »
I'm think that the AC compressor is designed to run all the time when the system is on except when the "Air Cond" toggle in the "OFF" position. I believe that it switches on with the defrost as well which is supposed to dehumidify the air.  I'm pretty sure I got that from the ACC manual but I've been reading soo much lately  :P

I just looked it up and it says that the AC compressor is always running when the temp is above 2deg C (36 deg F). It also says that it runs all the time in "bi-level" and "defrost" even if the switch is off!  Weird huh? 

Here's the link:

http://handbook.w116.org/Climate/83-600.pdf

Pretty good reading if you want to know exactly what the system is supposed to be doing and when!

I took the car on the road today  ;D  210 miles without a hitch. The AC just barely kept up with the heat but it was really hot down here in Ga.  today so I was pleased!  I left the house today at about 3:00 and got here at around 7:30.  Backroads, freeway and straight through ATL on I-75 like A BOSS!

I think this car is going to live up to my expectations  8)

About the V5 vs R4 theorizing  :D  My friend said he wouldn't trust parts store version of either compressor to last long.  That's why he likes the junkyard compressors from decent wrecked cars.  He said he's never had one fail because the OEM parts have a lot better quality control.  Pretty much the same story on any part though  ::)
Jon


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

BWalker82

  • Enthusiast
  • *
  • Posts: 39
  • Location: North Atlanta, GA
Re: ACC is functional!
« Reply #8 on: 22 May 2011, 05:52 PM »
The system is a lot like a Volvo's ACC setup I formerly had.  The system operated the compressor all the time (humidity control and to keep the systems seal's conditioned from dry rotting, the manual notes) unless the compressor was switched off on the panel.  It would continue to run even with the ACC blower off.  It was also odd that when you switched the compressor was switched OFF, an amber warning light illuminated on the compressor switch.  The switch was also overridden by selecting the DEFROST setting, but not bi-level or any other combination of airflow.

The system was, of course, entirely electronic and far more reliable than I'm dealing with now.  Yet I did have a condenser fail from stone impacts at the front of the lower air dam (a common fault/the later added screens to the lower air dam).
-BW

1980sdga

  • Vintage
  • ***
  • Posts: 813
  • Location: Ga. USA
Re: ACC is functional!
« Reply #9 on: 22 May 2011, 06:17 PM »
My '06 Cadillac has a similar system with the dual zone panel.  The "Thermostat" is digital and it's all electronic. GM LAN, which is a network than the different components use to communicate, takes the place of vacuum lines  ;D

I just think it's waaay cool to see how auto makers made these systems work 30 years ago and compare it to modern cars!
Jon


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

Hemersam

  • Classic
  • **
  • Posts: 355
  • Location: Dallas, Texas, USA
Re: ACC is functional!
« Reply #10 on: 25 May 2011, 05:21 AM »
FYI: I ran both my '78 280SE (r12) and '85 190D (freeze12) for eight minutes w/ ac on, and the 190D ended up 5 degrees cooler out of the vents. This is after I recently evacuated 134a from the 280 and refilled with r12; the r12 was a little cooler than the 134a. I'm going to re-do the diesel and put r12 back in it, tint the windows to the legal maximum , and see what happens. In Texas, you need all the cooling you can get.
Hemersam
BTW, both cars have a Sanden compressor.

1980sdga

  • Vintage
  • ***
  • Posts: 813
  • Location: Ga. USA
Re: ACC is functional!
« Reply #11 on: 25 May 2011, 03:02 PM »
FYI: I ran both my '78 280SE (r12) and '85 190D (freeze12) for eight minutes w/ ac on, and the 190D ended up 5 degrees cooler out of the vents. This is after I recently evacuated 134a from the 280 and refilled with r12; the r12 was a little cooler than the 134a. I'm going to re-do the diesel and put r12 back in it, tint the windows to the legal maximum , and see what happens. In Texas, you need all the cooling you can get.
Hemersam
BTW, both cars have a Sanden compressor.

Yep, pretty hot down here as well  ;D  My car is white and I'm also going to tint the windows. Tint also protects the interior as well so it's a win-win.

I wouldn't mind trying R12 but I have no idea where to get it  ???  It's actually cooling pretty well. In the evenings it's TOO cold with the AC on max but I have some amp issues so my thumbwheel doesn't work all the time.

I'm debating the UT kit vs an aluminum servo and new amp. My servo is working but the main body is cracked. I used oversized screws to fasten the valve to the body and it's not leaking but it wouldn't surprise me if it started.
« Last Edit: 25 May 2011, 03:22 PM by 1980sdga »
Jon


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

jbrasile

  • W116 Addict
  • ****
  • Posts: 1,217
Re: ACC is functional!
« Reply #12 on: 25 May 2011, 03:52 PM »
1980sdga,

I would go with an aluminum servo and new amp. The UT setup is not cheap either and the fact that it bypasses certain parts of the original system makes future diagnostics very tricky. An aluminum servo should last a very long time and if you have any problems you have the advantage of knowing what controls what. Just my .02

Tks,

Joe

1980sdga

  • Vintage
  • ***
  • Posts: 813
  • Location: Ga. USA
Re: ACC is functional!
« Reply #13 on: 25 May 2011, 04:03 PM »
1980sdga,

I would go with an aluminum servo and new amp. The UT setup is not cheap either and the fact that it bypasses certain parts of the original system makes future diagnostics very tricky. An aluminum servo should last a very long time and if you have any problems you have the advantage of knowing what controls what. Just my .02

Tks,

Joe

I think that's the route I'll end up taking. I have a pretty decent understanding of the system as it is now so I'd have to start over learning to troubleshoot with the UT system.  I've got a lot of time, frustration and sweat into figuring it out and that would be wasted if I changed systems  ;D

The fresh air element came in yesterday!  Thanks!

I'm pretty excited about getting the entire ACC system functioning 100%  I'm actually thinking about just getting a new amp and see if it solves my problem.  Mine keep failing intermittently with my home brew solder repairs.  I think I'll look into why they are getting so hot before going that route.

Thanks again,

Jon
Jon


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

jbrasile

  • W116 Addict
  • ****
  • Posts: 1,217
Re: ACC is functional!
« Reply #14 on: 25 May 2011, 04:08 PM »
Jon,

The risk of getting a new amp with a cracked servo is that you may end up burning the new part if all of a sudden the servo decides to lock due to its condition. Your current amp may be getting hot because the servo is sluggish to respond, I'd do it the other way around, get a new servo first and see if the current amp works ok, you may get lucky there.

Tks for confirming delivery of the fresh air element.

Joe