Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #31  
Old 07-28-2010, 08:55 AM
1986 300sdl 1985 380se
 
Join Date: Aug 2005
Location: West Monroe LA
Posts: 484
I have been reading along here and I have a very wild out there question. Have you checked the microswitch that shuts off the compressor at wide open throttle? It is very easy to locate in the engine compartment on the driver's side of the motor. Get someone to sit in the car with the car OFF and push accelerator to the floor. Watch your linkage and at full throttle it will hit a microswitch that shuts off the compressor. Perhaps something is hitting the switch when you drive because you say it works fine at idle. Perhaps the switch is stuck "ON". You can take the switch out an Ohm it to see if it is good.
Just a wild thought.
__________________
John
1986 300sdl
1985 380se
Reply With Quote
  #32  
Old 07-28-2010, 05:30 PM
Registered User
 
Join Date: May 2006
Location: Boston
Posts: 1,262
Good call, I'll definitely check this switch out. Thanks



Quote:
Originally Posted by brandlj View Post
I have been reading along here and I have a very wild out there question. Have you checked the microswitch that shuts off the compressor at wide open throttle? It is very easy to locate in the engine compartment on the driver's side of the motor. Get someone to sit in the car with the car OFF and push accelerator to the floor. Watch your linkage and at full throttle it will hit a microswitch that shuts off the compressor. Perhaps something is hitting the switch when you drive because you say it works fine at idle. Perhaps the switch is stuck "ON". You can take the switch out an Ohm it to see if it is good.
Just a wild thought.
Reply With Quote
  #33  
Old 07-28-2010, 05:39 PM
Registered User
 
Join Date: May 2006
Location: Boston
Posts: 1,262
Brian, this is exactly what is happening here with my compressor!
I'll try and jumper socket 5 and 7.
How big are chances that the relay itself is faulty versus the input parameters?



Quote:
Originally Posted by Brian Carlton View Post
This is typically a Klima issue. The Klima senses one of it's input parameters is not quite right and dumps the compressor clutch. The only way to get the compressor back is to shut down power to the Klima and reset it...........usually done by shutting down the engine.

My worst scenario was getting stuck in a heavy rainstorm in near 80 ambients. Water got onto the belt.........compressor slipped.........and the Klima dumped the clutch. Now I'm sitting in a steambath...............

Pull the Klima and jump sockets 5 and 7. This provides 12V directly to the clutch.........all the time. Drive the vehicle and monitor the vent temps. If they drop down near 40 and stay there, it's time to do Klima troubleshooting..........not a fun task, but necessary.
Reply With Quote
  #34  
Old 07-29-2010, 12:12 PM
Registered User
 
Join Date: May 2006
Location: Boston
Posts: 1,262
I checked the microswitch last night.
I tested continuity and the switch works just fine.



it works fine
Quote:
Originally Posted by brandlj View Post
I have been reading along here and I have a very wild out there question. Have you checked the microswitch that shuts off the compressor at wide open throttle? It is very easy to locate in the engine compartment on the driver's side of the motor. Get someone to sit in the car with the car OFF and push accelerator to the floor. Watch your linkage and at full throttle it will hit a microswitch that shuts off the compressor. Perhaps something is hitting the switch when you drive because you say it works fine at idle. Perhaps the switch is stuck "ON". You can take the switch out an Ohm it to see if it is good.
Just a wild thought.
Reply With Quote
  #35  
Old 07-29-2010, 06:17 PM
1986 300sdl 1985 380se
 
Join Date: Aug 2005
Location: West Monroe LA
Posts: 484
Please jump in and correct me if I am wrong, but here are the things that can make your compressor shut off. Low pressure switch on the drier, High pressure switch on the drier, micro switch for wide open throttle, speed sensor switch on back of compressor, and high coolant temp switch. These are the input parameters for the KLIMA. If all of your sensors are working then it must be a bad KLIMA relay.
Bridging sockets 5 and 7 together on the KLIMA socket will make the compressor come on and stay on. I believe Brian suggested doing this and seeing how your temps are doing.

My KLIMA worked perfectly about a month ago when my compressor failed and started to drag and make chirping noises. It immediately cut the power to the A/C clutch and now I have no A/C. I jumpered 5 and 7 and my compressor made a horrible screeching noise and I removed the jumper immediately. I am in the process of purchasing all of the parts I will need to get this working again. Luckily this is not my daily driver because it is pretty hot down here in Louisiana this summer. I figure by mid-fall I will have everything replaced.
__________________
John
1986 300sdl
1985 380se
Reply With Quote
  #36  
Old 08-05-2010, 02:42 PM
Registered User
 
Join Date: May 2006
Location: Boston
Posts: 1,262
I just wanted to let you know that I replaced my Klima relay by a icecube relay and since then my AC works well. Actually for the first time this summer I enjoy the cold. Before the AC just worked in park on the driveway.
Second issue of vent temps seems to be solved... I measured the initially 60F with a bad thermometer. Since I bought a non contact temp gun I can scan the temperature at the vent and last night after driving and freezing my old thermometer sticking in the vent showed 50F but the laser showed actualy 40F and below (as low as 30F!).
I checked also again if the monovalve is doing its job. A good way to test is popping the computer and check temperatures at the heater hose in the firewall underneath the computer.
So I believe after recharging R12 and putting icecube in I am back to great AC.
Maybe I will try and put a new klima relay in ..because the Klima realy is most possibly the culprit. The icecube is not providing same safety features as the original design.
Thanks for all your input. Martin
Reply With Quote
  #37  
Old 08-05-2010, 02:43 PM
Registered User
 
Join Date: May 2006
Location: Boston
Posts: 1,262
If anyone has a spare Klima relay for testing purposes- please let me know!
Reply With Quote
  #38  
Old 08-05-2010, 10:29 PM
1986 300sdl 1985 380se
 
Join Date: Aug 2005
Location: West Monroe LA
Posts: 484
I have to dig through my stash in the garage. I may only have one for a 617 motor ( 85 300sd ) but I am not sure. I won't be able to get out there till next week. I'll let you know what I find.
__________________
John
1986 300sdl
1985 380se
Reply With Quote
  #39  
Old 08-06-2010, 07:13 AM
Registered User
 
Join Date: May 2006
Location: Boston
Posts: 1,262
That would be awesome! Martin


Quote:
Originally Posted by brandlj View Post
I have to dig through my stash in the garage. I may only have one for a 617 motor ( 85 300sd ) but I am not sure. I won't be able to get out there till next week. I'll let you know what I find.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 07:43 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page