Climate control gremlins - Page 2 - PeachParts Mercedes-Benz Forum

cirrusman · #16 11-01-2013, 11:08 AM

Quote:

Originally Posted by SD Blue

F11 powers the blower motor controller and blower motor. I would be checking the blower motor and brushes. It is real easy to access on your model. Pull the front passenger's knee panel and IIRC it's only held in with 4 screws.

As the whole interior is dismantled right now, I got easy access to EVERYTHING...

I'll check out those brushes...

Quote:

My dad's SD had his defroster pod go partially bad. It took disabled the center vents. I would just replace the pod. They are not horribly expensive. The defroster pod is $60. Even if you mend it in one place, it could still fail in another spot. I suppose you could just liquid rubber the entire thing...not sure of the ramifications though.

$60 apiece is going to be a bit high for me right now... I've got 5 pods to take care of so that would rack up the bill to $300, in pods only. Since the whole interior is pulled apart now, I want to fix everything I can right now, but also for the cheapest price I can since I just lost my job 2 weeks ago... I will try the liquid rubber on all 5 and then report... If it works it would be a nice way to cheaply debug vacuum related issues on these climate controls.

sleepstar · #17 11-01-2013, 12:59 PM

cirrusman · #18 11-08-2013, 01:17 PM

Ok, so I've been working these last days in troubleshooting the thing. I didn't think that I'd have vacuum AND electrical problems at the same time, so I was stumped. I finally replaced all my rubber diaphragms on all pods to rule out vacuum leaks. Now vacuum does not leak at all. It's nice to see. Now, what I'm having is control unit issues. I tested all vacuum switchover valves with the ignition on and unit in the "off" position and all get nominal battery power. When unit is on the "on" position and temp is set on max heat, valves 4, 5 & 6 get no power, same when temp is set to max cold in the "econ" setting. On hot setting valve 4 should get no power, closing the vacuum, valve 5 should get power, and valve 6 should be closed. On cold setting, valve 4 should get power to open the valve and allow vacuum to the diverter flap's pod. Valves 1 to 3 get the correct power at the correct times, but 4-6 are getting no power when the switch is on. So I proceeded to get a new unit from my local PNP. The Unit I got is a remanufactured unit by ProgRama. Still the same exact problem! valves 1-3 getting correct power, valves 4-6 getting nothing on any temp setting. I don't see what exactly I'm missing here. I'm just about to just override 4, 5 & 6, install a couple of switches in the cabin and get power directly from fuse #10. Any ideas as of what route should I take here?

cirrusman · #19 11-08-2013, 01:18 PM

Quote:

Originally Posted by sleepstar

Yes, that's where I got the diaphragms

I got to say, really professional people and I got them really fast too! Thanks for the tip!

JamesDean · #20 11-08-2013, 01:56 PM

If I recall correctly, the switchover valves are not 100% controlled by the push button unit. The temperature regulator unit control some of them. I dont have access to a schematic but your problem might lie in that unit.

I cannot comment on programa's rebuilt climate contorl units but the few cruise control units that i have seen that came from them were not up to my standards. Old capacitors were not replaced and I did find a few cold solder joints.

cirrusman · #21 11-08-2013, 03:59 PM

Quote:

Originally Posted by JamesDean

If I recall correctly, the switchover valves are not 100% controlled by the push button unit. The temperature regulator unit control some of them. I dont have access to a schematic but your problem might lie in that unit.

I cannot comment on programa's rebuilt climate contorl units but the few cruise control units that i have seen that came from them were not up to my standards. Old capacitors were not replaced and I did find a few cold solder joints.

I did check the schematics, all power going to the switchover valves comes directly from the PBU. And yes, I opened the ProgRama unit and I did see some funky stuff so I just switched back to my old unit. I'm working in bypassing the PBU for switchover valves 4-6, which would be kind of cool too as it will give me the ability to have cool air on the front vents while having hot air for my feet at the same time

JamesDean · #22 11-08-2013, 04:07 PM

Quote:

Originally Posted by cirrusman

I did check the schematics, all power going to the switchover valves comes directly from the PBU. And yes, I opened the ProgRama unit and I did see some funky stuff so I just switched back to my old unit. I'm working in bypassing the PBU for switchover valves 4-6, which would be kind of cool too as it will give me the ability to have cool air on the front vents while having hot air for my feet at the same time

Are you planning on bypassing them electrically or vacuum wise? I did it with some T's and vac line on my 300D. Its quite nice to be warm on both sides rather than my just my left!

If you would like, you can always send one of those PBU's into me and I can have a look see.

cirrusman · #23 11-08-2013, 04:33 PM

I'm bypassing them electrically. I got 2 switches at autozone, one is an "on-off" 2 position switch, the other one is a 3 position switch; the 2 position switch will control switchover #4 which controls the diverter flap's pod, and assign switchover valves 5&6 to the 3 position switch as they cannot be opened at the same time, which go to the fresh air/recirculate flap.

Quote:

If you would like, you can always send one of those PBU's into me and I can have a look see.

As this is just part of a bigger project, and also this is my daily driver, I'll pass for now, thanks, but I'll keep you in mind when I decide to fix the unit for good. Right now I'm in the middle of not only troubleshooting the CC but also painting the interior back to Palomino, and re-covering my cracked dashboard with new vinyl. So far so good, I hope to beat the winter as I hate to work in the cold...

Junkman · #24 11-08-2013, 05:27 PM

As an aside, I talked to an old school MBZ mechanic today. He said to replace the auxilary water pump when you replace the PBU.

Also, for those with heat when going slow and none at speed OR intermittent heat even with the mono valve disconnected from the harness, replace the mono valve - the entire thing if you've replaced the guts and it still isn't working.

SD Blue · #25 11-08-2013, 05:34 PM

Depending on conditions, you may not be getting power to valves 4, 5 & 6 for several reasons.

Valve 4 is also controlled by the Cold Engine Lockout Switch and if the coolant isn't above 95 degrees, it may not be powered.

Valves 5 & 6 are controlled by the Temp Controller (through the ACC pushbutton unit) and the Cold Engine Lockout Switch is factored in as well.

There is a little bit of confusion with the "On" mode. Are you talking about "Total Ventilation", "Normal" or "Econ"? Was the engine at operating temp when you checked the valves for power?

There is a Component Mode Chart on this file that may help sort things out:
http://www.startekinfo.com/StarTek/outside/12253/program/ETM/ACC83-85.pdf

arzueck · #26 11-24-2013, 09:29 AM

Curious to know if there's been any further resolution to this.

I have a 2k mile road trip coming up and what I might need to fix in my system so that my feet dont freeze. Climate control works on defrost, high fan only. The system has vacuum going into the firewall (18-20Hg I think) but haven't investigated further.

I believe my temp sending unit for my dash gauge is not functioning. Could this also cause the cold engine lockout function on the other heater settings? Or is it driven my a separate sensor?

SD Blue · #27 11-24-2013, 10:18 AM

Quote:

Originally Posted by arzueck

Curious to know if there's been any further resolution to this.

I have a 2k mile road trip coming up and what I might need to fix in my system so that my feet dont freeze. Climate control works on defrost, high fan only. The system has vacuum going into the firewall (18-20Hg I think) but haven't investigated further.

I believe my temp sending unit for my dash gauge is not functioning. Could this also cause the cold engine lockout function on the other heater settings? Or is it driven my a separate sensor?

Are you getting heat in Defrost? If so, the monovalve may at least be opening.

More than likely, the problem is cracks in the solder inside the Pushbutton Controller. The circuit boards are arranged in an "H" pattern and the solder joints crack where they come together. Do a search here for "resoldering ACC" for posts with pics.

arzueck · #28 11-24-2013, 01:43 PM

Thanks Sam.

The air is nice and hot. But it dries my eyes and face out before anything in the car gets a chance to warm up

I'll do as you suggested.

cirrusman · #29 11-25-2013, 11:26 AM

As per the manual, the vacuum should be at 11.8 Hg, are you sure you're getting 18-20? Anyway, you may be getting vacuum from the pump, but are you sure it's getting to each switch valve? If the only air you're getting is from the defroster vents, sounds like the other flap actuators aren't getting any vacuum or the switch valves aren't getting the electrical power at the right time. On my car, it was both, so I ended up fixing all vacuum leaks, replaced a couple of diaphragms, and since the fresh air/recirculating flap wasn't working after all that, I ended up retrofitting an old manual flap actuator from an old Jeep... which works just fine. Don't think that you can't have both problems at the same time in these cars. :/