PeachParts Mercedes-Benz Forum

PeachParts Mercedes-Benz Forum (http://www.peachparts.com/shopforum/)
-   Diesel Discussion (http://www.peachparts.com/shopforum/diesel-discussion/)
-   -   Heater problem 84 300SD (http://www.peachparts.com/shopforum/diesel-discussion/373963-heater-problem-84-300sd.html)

The Gears 12-05-2015 01:15 AM

Heater problem 84 300SD
 
There is power to the mono valve but no ground from the Control Box
Also no power to the AC clutch when the Thermostat is on full cold.
The fan works OK but full hot air.
Am I missing something easy or do I have to pull the Control unit and do what.
Problem 2. Can the rear door swing stoppers or what ever they are called be serviced without removing from the door.
Mine are so stiff I had to undo them from the post.
Thanks

mannys9130 12-05-2015 01:53 AM

Can't advise on the AC.

The door check straps (the technical name) have to be removed from the door. Now, if you're lucky the things are still in one piece. If not, they are ripped and need to be replaced. Pull them out and inspect them. If both balls are still in the center sliding piece and everything is intact, use some ATF to free things up and then pack it with fresh grease.

sixto 12-05-2015 01:43 PM

Any number of things could be wrong but you're overdue for a PBU or at least reflowing the solders in your PBU if it's original.

For AC, check for continuity across the low pressure switch at the drier behind the left headlight. Usually the switch without pigtails is the low pressure switch. If there's no continuity, you're low on refrigerant and the compressor won't engage. Could also be a bad signal from the evaporator temp sensor. I forget if it's an interrupt along the compressor wire or a trigger into the PBU. Could also be a bad signal from the cabin temp sensor but defrost mode should override.

Sixto
83 300SD

trout007 12-05-2015 03:20 PM

Along these lines I have a 83 240D with manual dial temperature controls that are not connected to the valves. Does anyone know how to fix this? Is there a special bowden cable that goes between the dial and the valve?

charmalu 12-05-2015 04:12 PM

Are both of your temp knobs inop? or just one?
There is a metal cable that connects between the Knobs and the water valve in the Firewall.

There is a plastic chain with balls, sort of like the chain to pull a light switch on/off.
The plastic chain may have broke. There is no fix for this except to replace the assembly the knob turns to move the chain.

This thread may help.
http://www.peachparts.com/shopforum/diesel-discussion/339778-1983-240d-3-knob-climate-controls.html

You might want to start your own thread on this as it is the manual system,
not the same as the SD.


Charlie


sent from my pos computer

toomany MBZ 12-05-2015 04:42 PM

As mentioned, the door check strap needs replacement, sometimes the door will not close when broken.

You'll need to remove the inner door panel to gain access, but not the door itself.

The Gears 12-06-2015 10:28 PM

Quote:

Originally Posted by toomany MBZ (Post 3549357)
As mentioned, the door check strap needs replacement, sometimes the door will not close when broken.

You'll need to remove the inner door panel to gain access, but not the door itself.

Can I get away with just opening up the front edge of the door panel and sneaking the strap assembly out that way?
IE Pull the panel out, slit the plastic liner and slip my hand in to get hold of the thing.

toomany MBZ 12-06-2015 11:43 PM

Unknown, good luck.

Carpenterman 12-07-2015 09:11 AM

I think the check has two screws holding it to the inner door frame. You might be able to get a ratchet and socket in there to remove, but really, it isn't that much more trouble to take the door card off.


All times are GMT -4. The time now is 07:34 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website