haha no, i meant that i heard that they're cheap and they break after not too many uses if not well cared for.

the shop that did the ac told me they'd evacuate the system and re-fill it carefully, but i haven't done it yet because it still hasn't been really hot here again since that day, so I haven't been able to see if it still happens. I was thinking that when he did it, though, he could swap out the pressure switches.

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1980 300SD (daily driver), 1981 300D (Inca Red)

How disappointing considering the work was done by a Benz shop. I hope the forum helps you sort this out!!!!!!

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

We should have a beer together....

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

On a W116, the ETR (Evap Temp Reg) is mounted above the center vents on top of the evap case. The CC II FSM directs you to remove the dash to get to it, but I have adjusted it from the glovebox hole with a flexible carburetor adjustment tool. NOT easy, but possible.

Generally, if you adjust it enough to ice up the evaporator, airflow through the vents will cease. This will not shutdown the compressor or cause it to lock up.

Most W116's have a low pressure cutoff switch in the body drier and a high pressure or hi-temp switch in the top fitting of the drier that turns on the auxilliary fan.

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

Yes, the ETR does cycle the compressor as Leathermang has pointed out. Generally, it doesn't cycle in the shop, but you will feel it kick on and off at highway speeds. It is pre-set to cycle around 42°-45°F according to the service publications I have read and what I have learned from George Murphy.

Normal vent temps with R-12 at 70°F with 40% humidity (at 1500-2000 rpm) is about 41° to 45° according to the FSM.

My 1978 W116 would produce 48°F in the vent under these atmospheric conditions. A slight turn on the ETR screw brought the center vent temps down to 37°-38°F.

Vent temps never go above 48°-50°F even after idling for long periods...Robert

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

I live in California's Central Valley and it is frequently over 100°F in the summertime. Currently, I am running a new Wahler 80°C thermostat in my 300SD, replacing the 60°C unit that I have not been able to find a replacement for.

My car has a stock radiator. I replaced the 5 or 6 blade aluminum fan with a plastic unit having more blades, but that is my only modification. I run 25% coolant to 75% distilled water as SOP.

My car will not get as hot as your instruments are indicating and running the A/C will only move the needle up about a needle's width!!!

I have verified my gauge readings with a mechanical unit and heat gun as well.

I'm very curious about your temperature readings. Have you verified them???

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

No, I haven't yet verified them on this car. I almost bought an infrared thermometer the other day but didn't think I'd use it enough to justify its purchase. It could be that I'm getting improper readings. I think I should do that, though. It's going to get hot in Phoenix in no time.

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1980 300SD (daily driver), 1981 300D (Inca Red)

Just thinking here, if the AC system isn't able to keep up, is there any way to retrofit an electrically driven AC system into a car?? Of course a bigger alternator would be in order...

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All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic

A much bigger alternator. I think you're underestimating how power-hungry A/C systems really are. There's a reason the electric A/C units on RVs usually only run on 120V "shore power." A typical unit draws about 15A at 120V. To power one with an inverter your alternator would need to put out at least 150A, plus what's needed to make up for inverter inefficiency and to carry the other loads.

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1981 Mercedes 300TD, 1994 Honda Civic Del Sol
http://mefi.us/images/fuelly/smallsig-us/67195.pnghttp://mefi.us/images/fuelly/smallsig-us/103885.png

Maybe it's time for a Turbo-Diesel-Electric????

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

So, you're saying that an air conditioner to cool a car via electricity would take 1800 to 2000 W?? How much electricity does it take to run one of those systems in a hybrid??

__________________
All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic

A Hybrid has much more voltage and amperage capability than our old MBZ's. The Toyota Prius has a fluid radiator to cool the electronics!!!!!

__________________
Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

the prius hybrid electrical system is 300v...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Hi everyone! Long time, no post!

Well, there was a long delay because in Phoenix, AZ we had a good long cool spring. But summer is upon us and today it was 113F. To remind you, my engine was stalling sometimes when I engaged the compressor and when it was hot out, usually after recently turning off the engine for a short period of time.

I called the shop that installed the A/C when the problem first started, and they said they'd take a look at it, but we decided to wait until it got hot so they could observe the problem. I finally brought it in yesterday.

They told me they didn't find anything wrong. They told me the aux. fan wasn't working properly, which is wrong -- it works fine, and I've fixed it myself so I know it works.

They told me that the valves needed adjustment and the compression was therefore too low, but we adjusted our own valves and I think we did it well, although I am not going to argue this one too much. Either way the car seems to run fine and has decent power. (Here's a video of me accelerating without the A/C in case you want to know how it runs.)

They told me that they removed a little bit of freon because the pressure was 400lbs per sq. inch (this is what the owner told me but he was upset with me at the time because I didn't want to pay for the service visit -- they'd promised it would be covered under the warranty of the installation of the new compressor they'd installed earlier this year for $900, so I didn't really want to argue with him).

Finally, they told me they increased the idle.

Now, the car seems to idle a bit faster, and the compressor load seems to be much less when I switch it on. However, the air is not as cold as it was before (although today was unusually hot at 113F).

I bought some gauges and am ready to play with them. I would love to get this system optimized. Leathermang, you've been bugging me to get gauges on, so I"m ready now!

Thanks for everyone's help again...

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1980 300SD (daily driver), 1981 300D (Inca Red)

LOL,
Read the sticky at the top of the page to get back into the mind set...
Notice the parameters which are NEEDED for an accurate session with the gauges....
Remember also that you need a good fan blowing into the condensor. Squirrel cage much preferred. Your engine or aux fans are not enough to satisfy this requirement although that is what most people settle on... Windows down , high idle, pencil themometer in the center vent... ac on High but blower on LOW...
Have I forgotten anything ?

Have you cleaned AND straightened the fins on BOTH the condensor and radiator ?
Have you cleaned the fins on the inside of the evaporator ? A pain but needed.
Is any stock cowl around your fan still in place ?

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html