AC compressor not working HELP please!!

1986-1995 : 200TD, 200CE, E200, 260E, 300E 2.6, 300E 2.8, 300E, E320, 400E, E420, 500E, E500, 300CE, E320, 230TE, 300TE, 300D 2.5 TURBO, E300 DIESEL, 300TD, 300E 4MATIC, 300TE 4MATIC, E36 AMG
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Samarai
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AC compressor not working HELP please!!

Post by Samarai » Thu 23 Nov, 2017 1:14 am

Hi all, any things to check as to why my AC is not working would be really appreciated. Apologies if my question doubles up on previous posts.
I have a 1994 e280 and the A/C is puzzling me.
-I took the car to get gassed (They said it wasn't low on gas)
-I checked the KILMA relay (Whenever I remove it and plug it back in.. only when plugged back in the compressor kicks in for half a second then stops)
-I swapped it with a friend's KILMA relay and the same things happens (Exactly the same relay and his aircon works) so im ruling out the KILMA relay..
-I bridged connections 5 to 7 manually and the compressor kicked in and stayed on.. air blew cold and all works well.
- also tried copying my other mates e220 with this wiring change.
Image
But only the front two fans came on.. No compressor.

What else can I look into guys? what other things can I check?
Many thanks!!
My Silver 1989 230E W124
viewtopic.php?f=1&t=18619

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Ivanerrol
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Re: AC compressor not working HELP please!!

Post by Ivanerrol » Thu 23 Nov, 2017 9:44 am

The pressure switch on the drier causes the fans to come on when required and to activate the compressor clutch.
This maybe where your problem lies.
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
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W140 420SEL
W210 E240, E240
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MMWA
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Re: AC compressor not working HELP please!!

Post by MMWA » Fri 24 Nov, 2017 11:26 pm

could be literally anything, the operation panel the wiring or the compressor itself - there is an rpm sensor on my m104's compressor and if a stall is detected power to the clutch is cut, these sensors do fail. I'm not aware if your newer version is the same. I'd start by correcting the wiring at the receiver drier back to factory correct instead of this abortion and get cracking with a multimeter.
MMWA

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Tony From West Oz
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Re: AC compressor not working HELP please!!

Post by Tony From West Oz » Sat 25 Nov, 2017 12:31 am

Ivanerrol wrote:
Thu 23 Nov, 2017 9:44 am
The pressure switch on the drier causes the fans to come on when required and to activate the compressor clutch.
This maybe where your problem lies.
The only issue when replacing the pressure switch is that you then need to re-gas the system. Bypassing the switch is the best way to confirm the rest of the system is OK.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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Samarai
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Re: AC compressor not working HELP please!!

Post by Samarai » Wed 29 Nov, 2017 12:36 am

Ivanerrol wrote:
Thu 23 Nov, 2017 9:44 am
The pressure switch on the drier causes the fans to come on when required and to activate the compressor clutch.
This maybe where your problem lies.
thanks mate! I'll have to investigate the pressure switch.
I checked all the relays yesterday and no wires seemed loose plugging into the relays either.
My Silver 1989 230E W124
viewtopic.php?f=1&t=18619

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pina4greg
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Re: AC compressor not working HELP please!!

Post by pina4greg » Mon 18 Dec, 2017 6:50 pm

Just replacing my compressor in the W140. Purchased from Pelican parts.... any good recommendations for ac trade in West Australia??? To install it. Have had a quire of about $600
1992 W140 300se

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Tony From West Oz
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Re: AC compressor not working HELP please!!

Post by Tony From West Oz » Mon 18 Dec, 2017 7:24 pm

I replaced the compressor on my W202 C250 and it was a 1 hour job (from underneath with the car on stands). I then took it to my A/C man who gassed it up for $100.
Are you handy with a spanner?
It is not hard if you have the right tools.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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Ivanerrol
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Re: AC compressor not working HELP please!!

Post by Ivanerrol » Mon 18 Dec, 2017 8:08 pm

Tony From West Oz wrote:
Mon 18 Dec, 2017 7:24 pm
I replaced the compressor on my W202 C250 and it was a 1 hour job (from underneath with the car on stands). I then took it to my A/C man who gassed it up for $100.
Are you handy with a spanner?
It is not hard if you have the right tools.
+1

If you still any gas at all in your system, find your AC service man and have him vacuum the system out. Gets all the Gunk out.
I suggest you change your drier at the same time. Almost compulsory with a Compressor change.
Seals must be changed. There are generally 4 or 5 with the drier. Take the old seals to your AC service man - he will probably give you the seals for free. Don't get the sea;ls at the stealership - they will charge hundreds.
These are straight forward changeouts.
Do you have a V8 or 6?
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

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pina4greg
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Re: AC compressor not working HELP please!!

Post by pina4greg » Tue 19 Dec, 2017 12:08 am

Is there any problem with discharging the system? have changed water pumps, alternators, window regulators a..etc
1992 W140 300se

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pina4greg
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Re: AC compressor not working HELP please!!

Post by pina4greg » Tue 19 Dec, 2017 12:10 am

Where is your ac man To y?
1992 W140 300se

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Tony From West Oz
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Re: AC compressor not working HELP please!!

Post by Tony From West Oz » Tue 19 Dec, 2017 1:24 am

Harrisdale.
He does not have a workshop to replace the compressor and dryer. You will need to get the seals for compressor and dryer where you buy them.
send me a message when you are ready to re-gas the car. I will send you his phone number.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

'83 W123 300D 325000km (Wife's car Josephine - sold).
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE (SOLD)
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car - Sold)
'06 Ssanyong Musso Crew Cab 2WD Ute (OM662 diesel and Auto Transmission)

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pina4greg
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Re: AC compressor not working HELP please!!

Post by pina4greg » Tue 19 Dec, 2017 2:05 am

Thanks Tony...
1992 W140 300se

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benzy53
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Re: AC compressor not working HELP please!!

Post by benzy53 » Thu 04 Jan, 2018 7:20 pm

Have you solved your AC issue?
There are 3 main points to check.

1) bypass pressure switch
2) check if you have power to the clutch
3) check AC switch at the dashboard if no power at the clutch

benzy53

newMercowner69
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Re: AC compressor not working HELP please!!

Post by newMercowner69 » Sat 13 Jan, 2018 6:42 pm

Can you move/turn the compressor by hand?,
If not compressor clutch bearing's seized,
You'll need to dismantle/pull apart the compressor &have the bearing removed&refitted by pressing both on&off.

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Samarai
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Re: AC compressor not working HELP please!!

Post by Samarai » Mon 15 Jan, 2018 1:59 pm

MY AC PROBLEM FIXED!!! yay! :dance: (However! blower motor fuse bottom holder melting and dropped)
I had a local
auto masters check my gas levels and this was the 2nd place to confirm the level was perfect. Gas not too high or low.
It turns out the wiring to the back of the clutch was loose ie the wires had broken from the soldered loom connectors.
Some new solder and connections re-established successfully and the clutch was then engaging with the press of the aircon switch as normal yay!
This is the first time I had working aircon on this e280.

HOWEVER the blue 25A bottom fuse holder spring has sunk and the fuse tip (upper) on a few occasions now has disengaged from the top fuse terminal spring and naturally the blower motor has stopped alltogether until i wiggle the fuse up a bit to re-establish a connection.
Any ideas why this is has happened? none of the fuses have blown each time just the fuse losing contact and the plasti surround has melted a bit.. but maybe the blower motor is drawing too much power? the fuses are discolouring to a dirty light blue so to me indicating alot of heat but the fuses havent blown. Has this happened to anyone before?

Many thanks all!
My Silver 1989 230E W124
viewtopic.php?f=1&t=18619

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Christo C
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Re: AC compressor not working HELP please!!

Post by Christo C » Mon 15 Jan, 2018 6:36 pm

Fuse holder getting hot sounds like fuse was not fitting well or had some end corrosion - the junction heats up and resulted in the terminal melting the plastic. Perhaps the fuse is aluminium? Contact end corrosion is very common with those fuses; best that they are all replaced with copper or bronze fuses which wont corrode so easily. Also there must be plenty of tensionholding the fuses in.
If you can’t repair the fuse holder there may be another free fuse position you could use e.g in my car fuses E & F are not used as rhey are for electric front seat option....
~Christo
1986 230E W124.023 M102.982 Thistle Green Saloon "Janis"
Beaconsfield, SYDNEY

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AMG
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Re: AC compressor not working HELP please!!

Post by AMG » Mon 15 Jan, 2018 10:12 pm

Samarai wrote:
Mon 15 Jan, 2018 1:59 pm
Any ideas why this is has happened? none of the fuses have blown each time just the fuse losing contact and the plasti surround has melted a bit.. but maybe the blower motor is drawing too much power? the fuses are discolouring to a dirty light blue so to me indicating alot of heat but the fuses havent blown. Has this happened to anyone before?

Many thanks all!
Your Blower fan is on it's way out, and/or the blower motor rheostat is fkd. blower is an axial motor (think bench grinder) with two mouse wheels (septics call them squirrel cages) and the shaft rotates in a sleeve bearing - aka bush - which has no roller bearings or means of obtaining lubricant. Over the last couple of decades this has slowly worn out, you're likely to have excessive shaft endfloat, which in turn causes the brushes to prematurely wear and the bearing bush to fail, resulting in chirps or squeaks and slow fan speeds when the fan or AC is turned on. :clock:

Eventually, if left to it's own demise, the shaft can seize completely in the bushes and burn out the motor windings, or the rheostat, or both. Often the fuse cannot cope with the current load and overheats the holder, due to repetitive user attempts to turn on the fan and wonder why it's not blowing strongly or even at all. :think:

leaves, detritus and debris, lack of cleaning the wiper cowl, combined with rain, rotting leaf material etc eventually finds its way into the blower fan case and causes all of the above. :puke:

replace the fuse holder with another from the wrecker. refit a full compliment of new ceramic/copper fuses (not the junk ones) and use some deoxit on the contacts, followed by a thorough clean with CO cleaner, then use some switchlube contact spray sparingly on the clean contacts, fit the fuses. Should lasta great deal longer and will amazingly make many things work that for some reason weren't working before (.... I wonder why that is ;) ) :occasion5:

Then you have the blower fan and rheostat to attend to. remove wiper cowl, remove wiper arm & motor assembly, undo blower fan case clips, remove fan, clean everything in the case, with a vacuum, check fan for free and smooth shaft operation, replace the brushes (auto sparky if you can't solder) and lubricate the bushes, clean the plastic axial cages CAREFULLY with detergent. blw the motor winding clean with compressed air. replace, clean rheostat contacts etc, and make sure case is properly located and sealed. while you're in there, a good clean out of the general area is a wise thing, and checking for rust etc. This is an area where not many people venture into and it's easily cared for with minimal annual maintenance, which prevents many problems from becoming more serious issues.
Current:
1987 560SL 4sp. auto Signalrot "Stella"
1987 190E 2.3-16 5sp. man. Blauschwarz "Hermann"
1992 300CE-24 6sp. man. Perlblau / Iceblau "Gretel"
1992 Range Rover Classic 4sp auto Ardennes Green "Oswald"
2012 E63 AMG Speedshift MCT Diamantweiß "Klaus"
Previous:
1986 560SEL Anthracitgrau "Schultz" - In Mercedes Heaven
1987 190E 2.6 4sp. auto Signalrot "Sabine" - which now resides/owns Andrew M's Garage
1972 350SLC Astralsilber "Lurch" - now in the loving care of Craig B
1989 2.5-16 Blauschwarz 4sp. auto (parted) formerly owned by Derek/Hasan.
2012 Renault Sport Megane RS265 Trophy 8:08 6 sp. man. Liquid Yellow "Jean Rédélé"

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Samarai
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Re: AC compressor not working HELP please!!

Post by Samarai » Tue 16 Jan, 2018 10:49 am

wow many thanks for your thoughts lads! it means alot. I really dont mind being hands on with my cars, i love learning as i go! i certainly will now be avoiding using the fan unless absolutely necessary and will be investigating and cleaning the usually neglected under cowel area and crud that builds up. I'm pedantic with cleaning leaves off the cowl as they build up and or make sure the drainage pipes arent clogged. But sounds like my fuses and internals need some TLC.
I did swap fuses each time i noticed discolouration of the fuse or the fan stopped blowing just to be on the safe side.
Thanks again for your insight lads, very appreciated!
My Silver 1989 230E W124
viewtopic.php?f=1&t=18619

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