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
  #1  
Old 01-26-2011, 06:56 PM
Registered User
 
Join Date: Jan 2010
Posts: 51
DIY for manually controlling center and footwell vents in a W124

Since buying our first Mercedes a year ago - 87 300TD - I've gotten used to the automatic climate control system… for the most part. I had originally started a thread over here about changing nearly every aspect of the ACC, but I think the only two things I want to modify at this point is control over the center and footwell vents, and maybe someday getting control over the blower speed. The primary reason for wanting control over the vents is that in heating mode, by design, the center vents do not operate. When my hands are cold, I can warm one up with the side dash vent, but not the other hand. Turning on the center vent solves this problem. Also, sometimes the heat on my feet is too much.

Here's a write-up on how I tackled the first project - install a switch to manually choose between the center vent, the footwell vents, or both.

First, a little background information wouldn't hurt…

There are three ways in which air enters the cabin: defroster vents, dash vents, and footwell vents. Behind each vent is a flap that is controlled by a vacuum pod. The defroster vent flap and the side dash vent flaps are opened by a shared vacuum pod. The center vent flap is opened by its own vacuum pod, and the footwell vent flaps are opened by one (since 9/86) or two (before 9/86) vacuum pods. Since the side vents operate in unison with the defroster, we'll leave them and focus our attention on only the center and footwell vents.

Every flap in the car either opens or closes when its respective vacuum pod gets vacuum suction applied via a vacuum hose. Both the center and footwell flaps are normally closed when their vacuum pod doesn't have a vacuum. When the Automatic Climate Control (ACC) unit wants to open one of these flaps, it switches on one of the solenoids in the switchover valve block (Y7) to direct vacuum to a specific vacuum pod. When the ACC unit wants to close one of those flaps, the respective solenoid in Y7 is de-energized and vacuum suction is removed from that vacuum pod. At this point, the valve on Y7 is switched back to an open port on the back of the unit to allow air to flow into the vacuum hose and back into the pod. This is important because without this open port, the vacuum pod would stay "activated", and it wouldn't be able to return to it's normal position (closed in the case of the center and footwell pods).

Y7 has a valve on the top where vacuum is always present (sucking, if you will). There are 7 valves on its side that go to 5 different pods. (Two of the pods, the defroster and fresh air pods, each get two hoses going to them to allow for each pod to have two activated states. Applying vacuum to the first valve on the pod makes it partially open a flap, apply vacuum to the second valve on the pod and it will fully open that flap.) Each of the valves on the side of Y7 have a restrictive plug in them to slow down the flow of air. This creates a delay in the opening and closing of each pod which makes the process of opening and closing flaps more gradual, less loud, and probably extends the life of the vacuum pods. Each valve has a different amount of restriction, and on my unit valve number 2 had no restrictive plug (not sure if it use to or not). The back of Y7 contains all the open ports for each valve. When the solenoid for a valve is de-energized, that valve is open to one of these ports for air to flow through to the vacuum pod allowing its internal spring to return it to its normal state.



The ACC unit is programmed to send heat primarily through the defrost vents and the footwell vents, keeping the center vents closed. It is programmed to send cold air through the defrost vents and the center vent, keeping the footwell vents closed. If we want to have manual control over the opening and closing of the center and footwell flaps, then we need to make sure we set our mod up to work in both the summer and winter. Fortunately it's pretty easy to do.

Since the ACC unit always has one of the two flaps open (with the exception of defrost mode), we can combine the two valves that govern the center and footwell pods to give us one vacuum source that's always on when we're in one of the non-defrost modes, and regardless of whether we're heating or cooling. Then we'll split this new combined vacuum source to two separate switchover valves that will connect to the center vacuum pod and the footwell vacuum pod. (I'll call these new switchover valves vacuum relays to keep things clear.) We'll wire these vacuum relays to a new switch on the console. In order to use a stock Mercedes switch with three positions, we'll need to have our vacuum relays perform the opposite function than Y7 does. Namely, when the vacuum relays are not energized, vacuum flows to the pods activating (opening) them. When the vacuum relays are energized, vacuum is blocked, and the pods are connected to an open (non-vacuum) port.



The switch will be a rocker switch with three positions:
  • up - center vents only (footwell flaps closed, footwell vacuum relay energized)
  • middle - center and footwell (both vacuum relays de-energized)
  • down - footwell vents only (center flap closed, center vacuum relays energized)

We need a switch that will stay in each of the three positions. The way to connect the hoses to our vacuum relays and the way to wire them to the switch will depend entirely on what switch you will use. I looked for a switch with pictures that could depict upper and lower vents, and found one close enough, but it wasn't the right type. It was a rear window screen switch (124-821-04-51), but the rocker didn't stay in the up or down position, and the caps are too integrated with the inside mechanisms to move it to another switch. If anyone can figure out how to modify this switch, that'd be awesome! Other switch suggestions are welcome too.



There are probably more options than I found at a junk yard covered in several feet of snow (I couldn't get into half the cars), but I settled on the interior dome lamp switch (124-821-02-51).



In order to make room for this switch, I found a console panel that matches my interior, but with one extra switch opening. If you have installed a new stereo that doesn't use the factory fader, you could use the space where the fader switch is - I'll cover both options.



You will need:
  • two vacuum relays (vacuum switchover valves) 0015407097, $20 each or less from junk yard - many models have at least two of them
  • wiring harness for the vacuum relays, or four butt connectors that'll fit over the pins
  • 5' of vacuum hose - I used .170" ID polyethylene tubing which fits really well over the valves on the vacuum relays
  • two 3/16" hose couplers
  • two 3/16" hose three-way couplers, wyes are better than tees, or you could use one four-way coupler
  • two check valves (pet stores have nice small ones)
  • an ON-OFF-ON SPST rocker switch for the dash, with wiring harness - I used an interior dome lamp switch (124-821-02-51), but others will do
  • any extra junk switch and harness for an extra pin and socket to properly rewire the above switch to illuminate with the other switches at night - find one where the pin is easy to remove (124-820-34-01 works great)
  • several feet of wire, preferably a few different colors
  • electrical connectors (I used what I had, you may want to do things differently, so I won't list every single one)


1) Remove the glove box liner. There are 7 plastic rivets along the inside of the glove box (4 on top, 3 on bottom). Pry up the rivet with a flathead screwdriver about a half inch. You will then be able to remove the two-piece rivet. Unscrew the latch at the top.

2) Pry down the front of the light cover and pull it out to disconnect the clip. Pull down on the top center of the glove box liner about 1/2" then pull out.




3) Next unscrew the glove box door hinges. You can then remove the arms from the dash by letting the door hang down (in its upright position, like when it's closed, only dangling down below the opening), then pull the arms out of the rubber opening. You can alternatively pry out the rubber grommets to make more room for getting the arms out.




4) Locate the vacuum switchover valve (Y7) at the left of the glove box opening, on the right (passenger) side of the air box.




5) Remove the center console panel by unscrewing the two screws directly above the stereo. Gently pull outward from the bottom of the panel and it will hinge at the top until you can pull the panel off.




6) Unscrew the ACC unit. There are two large screws and four smaller ones. Pull the ACC unit out and leave it hanging to the driver's side. You can keep it plugged in.





7) If you are using the fader switch hole for your new switch, then you'll need to remove the lower center console.

Continued...


Last edited by zebellis; 01-26-2011 at 09:50 PM. Reason: added a few sentences explaining "why"
Reply With Quote
  #2  
Old 01-26-2011, 06:57 PM
Registered User
 
Join Date: Jan 2010
Posts: 51
8) Pry back the carpet under the armrest with a screwdriver being careful not to use the wood panel as leverage - as it will likely chip or crack.




9) Unscrew the exposed screw. Put the shifter into reverse or drive (with the car off!). Lift up on the panel and it will hinge at the front until you can pull the panel off.






10) Remove the fader switch. If you are using this option, then it's likely that you've already been messing with these wires to access the speaker wires. In any case, you need to pull the wires down through the bracket holding the window switches, and out into the open area near the shifter to get them out of the way. This may involve cutting or unsoldering the wires. Do this at your own risk! I did this last year when I replaced my stereo, so I don't have any photos. The gray/blue wire that powers the light in the switch will come in handy with our new switch.




11) In the back of the glove box compartment is a group of wires that lead to the glove box light. Carefully remove a few inches of the sheath. Tap into one of the black and yellow striped wires to get power for our vacuum relays. Run the wire under the vacuum switchover valve (Y7) and through to the center console compartment where you will be installing your switch. 4-5 feet of wire should be enough.




12) You could use the brown wire on the lead to the glove box light for ground, but I chose to run a new wire to the bolt holding the black crossmember to the frame. If you want to do it the hard way (like I did), you'll need to remove the passenger side vent, and move the large air duct out of the way (it's actually not that hard). The vent has four spring tabs holding it in place. Using four small screwdrivers or coat hanger wire, pry the bottom spring tabs up and the top ones down enough to release pressure on the surrounding dash. The vent should slide out, but it may take some persuasion. Carefully disconnect the illumination bulb.



View through the passenger side vent opening



13) The ground wire only needs to be long enough to reach into the center of the glove box opening, but with plenty of slack. This is where our new vacuum relays will go. There's plenty of space between the crossmember and the side vent air duct to tuck the relays so we can get the glove box back in. You'll need to split this wire off so that we can make two ground connections - one on each of the vacuum relays.

14) On the front of Y7 are numbers 1-7 corresponding to each valve. Number 3 goes to the footwell pod, number 4 goes to the center pod. Disconnect them, making a note of which is which (you might want to label these if you want to undo everything).

15) Using the photo, cut your hose pieces and put everything together to match mine. It's very important to install the check valves. At any given time, one of valves #3 or #4 on Y7 will be open to the air via the open ports on the back of Y7. The check valves will prevent Y7 from sucking a vacuum through one of our new hoses connected to #3 or #4 and getting unlimited fresh air from the open port on the back of Y7 for the opposite valve. That would prevent the vacuum suction from getting to the pods. It's also important to leave the top valve on our new vacuum relays open to allow air to flow through to the vacuum pod when we want to turn that pod off (by energizing the respective vacuum relay).



16) I'm not sure if it matters which side of the vacuum relay you connect ground to, but I just did whatever was done in the car that I took the vacuum relays from. (You can also look in your own car). So, in that case, connect a ground wire to each vacuum relay using the pin on the same side as the part numbers. Connect a separate wire to each of the other pins (on the same side as the little diagram), and run these two wires through to the center console compartment where your power wire went earlier (step #11).

17) Tuck the vacuum relays, hoses, and wires down in the space at the bottom of the glove box compartment between the black crossmember and the black air duct. I tucked all the hoses with the check valves under the bracket holding the crossmember, and left the original hoses going to the vacuum pods above that bracket. Do whatever works for you, but be careful not to disconnect the center vacuum line from the rubber angle connector that leads into the middle of the air box where the center vent pod lives. You should be able to see this with the ACC unit pulled out of the way (see picture in step #6).





18) You can test your creation at this point. The key is to use a setting on the ACC that you know will produce air from either one of the center or footwell vents. Turn the car on and press one of the non-defrost buttons on the ACC unit (warm the car up if necessary). None of the three wires you pulled through the dash (one hot and two from the vacuum relays) should be connected to one another - this way air should be coming out of both of the center and footwell vents. If you connect one of the relay wires to hot, that vacuum relay's solenoid should energize and turn off flow to it's respective pod - stopping the flow of air to that vent. Try it with the other wire to test the other vacuum relay.

Continued...
Reply With Quote
  #3  
Old 01-26-2011, 06:58 PM
Registered User
 
Join Date: Jan 2010
Posts: 51
Now we're on to the switch. This next section will depend greatly on the type of switch you are going to use. If you're not using the same type of switch that I am, then you're on your own. The only thing you need to know is that with the way the vacuum relays are configured with the hoses, powering the relay will stop the vacuum flow to the pod, closing the flap. If your switching solution requires that you do the opposite (energize the vacuum relay in order to send vacuum to the pod, opening the flap), then you just need to move the hoses from the bottom (valve #1) of the vacuum relays to the top (valve #2). Leave the hoses connected to the right angle valves (#3). This document, page 8, helps describe the vacuum relays (they're called vacuum switchover valves).



You can install the switch as is, but the way we're using it, the illumination LEDs do not work when the switch in is the "up" position. So we need to install a new ground pin to separate the illumination circuit from the switch circuit. Steps #19-26 are optional, but I recommend them. If you want to skip them, then I would not recommend connecting an illumination wire to this particular switch.

(OPTIONAL - but recommended)
19) Pry off the cover of the junk wiring harness. You should be able to easily remove any one of the sockets, keeping the wire attached.



20) Pry off the cover and base of the junk switch you have. You need to remove one of the pins. Find one that can easily be disconnected from the inner wiring, unsoldering where necessary. Usually the pin connected to a resistor or an LED is easiest. Others may be pressed into metal plates or washers. In either case, the pin is press fitted into the plastic and can be very hard to pull out. I found that pressing the hot soldering iron against the exposed portion of the pin will heat it up enough to melt the plastic around it just enough to ease its removal. You could also cut the plastic around it. Once the pin is out, set it aside with the socket from the last step.

Here's the switch I used for the pin:


Pry off the bottom:


This is an easy pin to remove. Just unsolder the resistor and heat the pin to melt the plastic surrounding it. Slide it out.


21) Now pry of the one side of the cover of the wiring harness you got with your new switch. You'll need to pry off the side with the numbers 1, 3, and 4. Add the socket you removed in the step #19 to spot #4. Close the clip.





22) Take the new switch and remove the top cover, keeping in mind how it goes back on. Look inside and take a picture or note how it all fits together. Remove the ball bearing and any loose springs, set them with the top. (I didn't have any photos of the switch before I altered it, so I used a newer version of the switch with the same insides for these next three photos.)




Watch out for these ball bearings, shafts, and springs. They will fall out.


23) Flip the switch over and remove the bottom (gray plastic) by prying with a very small screwdriver to lift the plastic case free from the four little tabs. Be careful not to break the plastic.



24) Find the hole labeled #4 in the bottom of the switch. Take the pin you removed in step #20 and press it firmly into that empty hole from the top. Be sure it's in there very tight.

25) Notice how one lead of the LEDs is soldered to the metal strip connecting pin 1 to 5. Carefully unsolder this lead. Use some small needle-nose pliers to bend the lead over to your new pin in hole #4. Solder it to that pin.




26) Put the switch back together. Make sure it fits into your wiring harness.

27) If you are installing the switch into the lower console in place of the fader switch, you will probably need to shave off a small amount of plastic from the four little ridges on the sides in order for the switch to rest low enough in the empty space left by the fader switch.



28) Feed the wires of your wiring harness through the appropriate opening above the ACC unit (or in the fader spot). Connect the wire like this:
  • pin 2 (gray/blue): power for the illumination - find one to tap into, usually a gray/blue wire, I used one from my old fader switch
  • pin 4 (what ever color you got with your socket): ground for illumination - again, I used one from my old fader switch
  • pin 3 (two brown/white wires together): hot from the glove box light (or other source that's only on when the key is in the "accy." "run" or "on" position) - this powers our vacuum relays
  • pin 1 (brown): connect to the vacuum relay for the footwell pod
  • pin 7 (brown/blue): connect to the vacuum relay for the center pod



29) Test the switch.
  • When the switch is in the upper position, it energizes the footwell vacuum relay and no air comes out of the footwell vents.
  • When the switch is in the center position, neither of the vacuum relays are energized and air comes out of both center and footwell vents.
  • When the switch is in the lower position, it energizes the center vacuum relay and no air comes out of the center dash vents.
If the upper and lower switch positions do the opposite of what is described above, just swap the wires to pins 1 and 7.

30a) Remove the plastic thing covering all the wires to the switch harnesses behind the switches. Press in the four tabs (two above and two below the switches). It's a tight fit behind there, but it's flexible so just work it out to the right and down.



Insert your new switch wiring harness (without your switch plugged into it) in through the back of the empty spot above the ACC unit.


If you need to move or rearrange any switches, the harnesses will come free if you apply a little pressure with a screwdriver on each side of the harness.


-OR-

30b) If you are putting your switch into the fader switch spot, first rest the switch into the empty spot and make sure it rests level with the passenger window switch. Cut extra off the plastic ridges (see step #27) if necessary. Put the switch into the harness and clip it up onto the back of the wooden console panel (just like the fader switch did). I do not have any picture of this.

31) Tuck all wires out of the way and put the ACC unit back in place.

32) Install your new console panel with the opening for your new switch (or if you used the fader spot, screw the lower console panel back in place).

33) Put the glove box door back on, followed by the glove box liner (don't forget to pull the wires for the light out through the opening in the liner), then the latch at the top of the liner.

34) Enjoy!

-Zeb
Reply With Quote
  #4  
Old 01-26-2011, 08:13 PM
sjh sjh is offline
Banned
 
Join Date: Oct 2009
Posts: 580
Nicely Done

Greetings,

A very nice job on the DIY.

I have also been doing a similar project and I benefit from your comments and write-up.

One other thing I did to my HVAC system was to permanently engage the 80% recirculation pods whenever the unit is operating. While I like my car even small amounts of diesel fumes bother me and engaging the 80% recirc helps.

Great job.

Stuart
Reply With Quote
  #5  
Old 01-26-2011, 08:40 PM
Registered User
 
Join Date: Aug 2010
Location: UK
Posts: 331
1 question.

Why?

I don't get it.........
Reply With Quote
  #6  
Old 01-26-2011, 08:49 PM
mommamia
 
Join Date: Dec 2007
Location: Maryland
Posts: 508
Nice
__________________
1995 E420 152k
1991 300D 2.5 348116 daily driver
1992 300E 2.6 196k-work in progress(head gasket)
2002 BMW 745Li 93k
Reply With Quote
  #7  
Old 01-26-2011, 09:43 PM
Registered User
 
Join Date: Jan 2010
Posts: 51
Quote:
Originally Posted by W124 E300D View Post
1 question.

Why?

I don't get it.........
Oh. Woops. I'm glad you asked. I totally forgot to explain that. I edited the very first paragraph to explain why... But I'll add it here too.

Basically, the primary reason for wanting control over the vents is that in heating mode, by design, the center vents do not operate. When my hands are cold, I can warm one up with the side dash vent, but not the other hand. Turning on the center vent solves this problem. Also, sometimes the heat on my feet is too much. Furthermore, in cooling mode, only the center vents operate, not the footwells. I'd rather just have a switch.
Reply With Quote
  #8  
Old 01-27-2011, 02:52 AM
Registered User
 
Join Date: Nov 2005
Location: Iowa City, IA
Posts: 1,647
That is awesome. Very slick interface. Impressive right up. Thanks for taking time to do this. I would like to do this if i had a lot of time. It looks hard.

I have a question your experience can probably help me with. I just want to simply open the center vents all the time and i can close them with the dial in the middle of the vents on the dash. I did this on my W123 just by reaching behind glove box and taking the arm from the vacuum pod to the vent flap and disconnecting it and bending it over the flap to permanently hold it open. Then i disconnected the vacuum line to the pod and plugged it. It was ideal because its not dependent on those troublesome acc components.

I would like to do something like this on my W124s. Did you notice if you can get at center vent flap easily to permanently prop it open or remove it? (Ohh, i just had an idea -- I could drill holes in the flap with a 1 inch paddle bit then sawzall remaning parts off. Sounds dangerous though ) That would be my #1 solution.
#2 would be to run a direct vacuum supply to the center vent POD. That looks pretty easy from your pics. Just T off the white supply tube at the top of the Vacuum Switchover Y7 valve and connect to 4 ?

Do you really get too much heat on your feet in your wagon? My feet are usually close to cold. I plenty of air down there it is just not directed at my feet . I'll have to put some redirection down there i guess.

Thanks again for write up and pics.
__________________
What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius
Reply With Quote
  #9  
Old 01-27-2011, 07:41 AM
Registered User
 
Join Date: Aug 2010
Location: UK
Posts: 331
Quote:
Originally Posted by zebellis View Post
Oh. Woops. I'm glad you asked. I totally forgot to explain that. I edited the very first paragraph to explain why... But I'll add it here too.

Basically, the primary reason for wanting control over the vents is that in heating mode, by design, the center vents do not operate. When my hands are cold, I can warm one up with the side dash vent, but not the other hand. Turning on the center vent solves this problem. Also, sometimes the heat on my feet is too much. Furthermore, in cooling mode, only the center vents operate, not the footwells. I'd rather just have a switch.

hmmmmm

The standard design will chuck cabin temperature regulated heat out the footwells / side vents / screen vents depending on where you set the position of the right hand control.

The amount of heat output is regulated by the thermostat for each side, and depends on cabin temp vs thermostat temp, and of course fan speed.

The side vent is there, not to "warm your hands" but to provide a convenience store like hot air curtain so you can drive with the window cracked down (smokers) and not get the cabin cold.

If you have one cold hand, then your cabin temperature is not up to spec, so you have a separate thermostatic control problem that this mod is not going to address.

My W124 has one of the best heating systems ever fitted to a car, I get warm air within 400 yards of an overnight cold start, and within 800 yards the cabin heating system is basically up to speed.
Reply With Quote
  #10  
Old 01-27-2011, 07:53 AM
Rafi's Avatar
Registered User
 
Join Date: Jan 2003
Location: Garden State
Posts: 474
Quote:
Originally Posted by zebellis View Post

Basically, the primary reason for wanting control over the vents is that in heating mode, by design, the center vents do not operate. When my hands are cold, I can warm one up with the side dash vent, but not the other hand. Turning on the center vent solves this problem. Also, sometimes the heat on my feet is too much. Furthermore, in cooling mode, only the center vents operate, not the footwells. I'd rather just have a switch.
First, superb job, including the documentation.

Second, why don't they make heated steering wheel, they make heated seats which my ass does not need warming, but heated steering wheel would be nice.
__________________
2010 ML350 Bluetec
2012 Mustang Convertible
Reply With Quote
  #11  
Old 01-27-2011, 08:36 AM
Registered User
 
Join Date: Aug 2005
Location: Toronto
Posts: 394
Quote:
Originally Posted by W124 E300D View Post
hmmmmm

The standard design will chuck cabin temperature regulated heat out the footwells / side vents / screen vents depending on where you set the position of the right hand control....

etc.
this doesn't apply to the write-up presented here. you have a different heating system, we have ACC in north america. two very different systems working in very different ways. some similar components but the control of the systems is completely different. i have a euro 124 and i know what you're talking about but it doesn't apply at all to what the OP is trying to accomplish.

it's an awesome write-up and incredible amount of thinking and design went into this. i wonder also 'why' but the answer in this case must be 'because i can'. even if i don't understand why someone would go to such lengths, and rationalize it for warming their hands - i warm my hands on the vents too, it's cold up here in toronto, i would never go to such lengths for such a mundane 'improvement'.

the fact is that someone with limited ability to think this concept through could simply follow these instructions and achieve the results perfectly. it's no mean feat to put this together - i say 'well done'
__________________
________________

punkinfair
Reply With Quote
  #12  
Old 01-27-2011, 08:56 AM
winmutt's Avatar
85 300D 4spd+tow+h4
 
Join Date: Apr 2006
Location: Atl Gawga
Posts: 9,340
Great documentation job. Personally I would like to fix the air recirc if anything. Drives me up the wall that it turns off after 15min. I would love to see it cycle open every 15min to get fresh air in but then come back to recirc until the button or car is turned off.
__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1987 300D Sturmmachine
1991 300D Nearly Perfect
1994 E320 Cabriolet
1995 E320 Touring
2001 Eurovan FOR SALE
1985 300D car, sold and missed.
OBK #42
Reply With Quote
  #13  
Old 01-27-2011, 11:09 AM
Registered User
 
Join Date: Aug 2010
Location: UK
Posts: 331
Quote:
Originally Posted by punkinfair View Post
this doesn't apply to the write-up presented here. you have a different heating system, we have ACC in north america. two very different systems working in very different ways. some similar components but the control of the systems is completely different. i have a euro 124 and i know what you're talking about but it doesn't apply at all to what the OP is trying to accomplish.

Now THAT is interesting....

MB USA seems to be on another planet in many ways, not least of which is calling everything a 300D
Reply With Quote
  #14  
Old 01-27-2011, 12:18 PM
soothappens's Avatar
Registered User
 
Join Date: Nov 2009
Location: Alamo city
Posts: 494
Wow!! Nice write up.

Makes me wish I owned one just so I could try it.
__________________


Experience : what you receive 3 seconds after you really needed it !!




86 300SDL 387,000? Motor committed suicide
81 300SD 214,000 "new" 132,000 motor
83 300SD 212,000 parts car
83 300SD 147,000

91 F700 5.9 cummins 5spd eaton 298,000
66 AMC rambler American 2dr auto 108,000
95 Chevy 3/4 ton auto 160,000
03 Toyota 4runner 180,000 wifes
Reply With Quote
  #15  
Old 01-27-2011, 02:49 PM
Registered User
 
Join Date: Jan 2010
Posts: 51
Quote:
Originally Posted by biopete View Post
I would like to do this if i had a lot of time. It looks hard.
It's actually not hard at all. It took me way longer to make the write-up than it did to do the mod. It helps to have all the stuff acquired first.

Quote:
Originally Posted by biopete View Post
I have a question your experience can probably help me with. I just want to simply open the center vents all the time and i can close them with the dial in the middle of the vents on the dash. I did this on my W123 just by reaching behind glove box and taking the arm from the vacuum pod to the vent flap and disconnecting it and bending it over the flap to permanently hold it open. Then i disconnected the vacuum line to the pod and plugged it. It was ideal because its not dependent on those troublesome acc components.

I would like to do something like this on my W124s. Did you notice if you can get at center vent flap easily to permanently prop it open or remove it? (Ohh, i just had an idea -- I could drill holes in the flap with a 1 inch paddle bit then sawzall remaning parts off. Sounds dangerous though ) That would be my #1 solution.
#2 would be to run a direct vacuum supply to the center vent POD. That looks pretty easy from your pics. Just T off the white supply tube at the top of the Vacuum Switchover Y7 valve and connect to 4 ?
The flap for the center vent is buried in the air box and would require taking the dash off to access it. Check this out. I would definitely NOT do the first option you mentioned. Yikes! The second option would be a lot easier - disconnect the hose from valve 4, cap valve 4, run a new line from the hose to a tee on the white supply line.

Quote:
Originally Posted by biopete View Post
Do you really get too much heat on your feet in your wagon? My feet are usually close to cold. I plenty of air down there it is just not directed at my feet . I'll have to put some redirection down there i guess.

Thanks again for write up and pics.
Sometimes. It's more of a problem without the mod because if a passenger is colder than you, cranking up the heat will heat up the footwell compartment pretty quick. With the mod, I can just shut off the footwell vents and direct the center vents towards the passenger.

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 07:56 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2022, 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