ACCII Help - PeachParts Mercedes-Benz Forum

johninva · #1 08-19-2009, 09:23 PM

All push buttons were working great. Heat and temperature control, great - just no AC - leaky system. During AC r&r I replaced the expansion valve. I did some pushing and tugging on the on the bundle of vac lines that were in my way. Now only the defrost button makes the blower function. Im hoping i just pulled a vac line loose from the back of the push button unit ? how do i get that thing out to see the back of it ?

JimFreeh · #2 08-20-2009, 06:34 AM

I suspect multiple problems.

If you have the horizontal tow of buttons, the push button control unit is electrical only and distributes vacuum via electrical signal to a distribution block for the vacuum.

Moving vacuum lines would have no effect on triggering the fan.

Jim

johninva · #3 08-20-2009, 08:08 AM

accII = vertical row of buttons & evil servo. PO went through the system with a fine tooth comb. new vac pods, new servo. everything worked great except no cold air. I r&r the AC and BAM ! no blower on any setting other then defrost.

It is my understanding from reading on the forum that a large vac leak will cause this default condition.

I was hoping the push button unit would come out so I could look behind it, hopefully to reveal a vac line that had come loose when i while i was replacing the expansion valve. However it does not seem to do that.

Does the console have to be removed ?

johninva · #4 08-20-2009, 01:54 PM

im looking at the service manual on the cd and am having a hard time even figuring where to start trouble shooting.

Can I start by getting a confirm or deny that the blower has a master switch that is vacuum controlled

whunter · #5 08-21-2009, 02:22 AM

Quote:

Originally Posted by johninva

All push buttons were working great. Heat and temperature control, great - just no AC - leaky system. During AC r&r I replaced the expansion valve. I did some pushing and tugging on the on the bundle of vac lines that were in my way. Now only the defrost button makes the blower function. Im hoping i just pulled a vac line loose from the back of the push button unit ? how do i get that thing out to see the back of it ?

Here is what you need.

Servo service manual
http://www.peachparts.com/shopforum/showthread.php?p=2053754

Have a great day.

kerry · #6 08-21-2009, 10:08 AM

Quote:

Originally Posted by johninva

im looking at the service manual on the cd and am having a hard time even figuring where to start trouble shooting.

Can I start by getting a confirm or deny that the blower has a master switch that is vacuum controlled

Yes it does and it's visible behind the glove compartment. Green I think.

meltedpanda · #7 08-21-2009, 10:27 AM

defrost only mode is the failsafe built into the system, so look to the PB unit

johninva · #8 08-21-2009, 01:45 PM

Quote:

so look to the PB unit

Is the pb the servo or the amplifier ?

kerry · #9 08-21-2009, 01:57 PM

pb=pushbutton unit but I don't think that comment is applicable when working on the evil servo version.

meltedpanda · #10 08-21-2009, 02:12 PM

I still think it holds true, you have to rule out the PB unit ., particularly since this is the area "last messed with"

johninva · #11 08-21-2009, 03:25 PM

Quote:

Quote:
Originally Posted by johninva View Post
im looking at the service manual on the cd and am having a hard time even figuring where to start trouble shooting.

Can I start by getting a confirm or deny that the blower has a master switch that is vacuum controlled
Yes it does and it's visible behind the glove compartment. Green I think.
__________________

Ill look again but i had glove box out and i dont see any vacuum lines going to the blower area.

kerry · #12 08-21-2009, 04:41 PM

Quote:

Originally Posted by johninva

Ill look again but i had glove box out and i dont see any vacuum lines going to the blower area.

Master switch is above the blower, higher up, behind the glove compartment. Now wait a minute, I'm talking about a W116. Perhaps it is in a different location on a 123. On the W116 there are two vacuum/electric switches and they are mounted on the bottom of the plenum for the defrost(?)

johninva · #13 08-21-2009, 05:12 PM

I went and pulled the glove box. dont see it. Can anyone help me find this guy on a W123. I fell like its got to be something simple like that. Everything is newly renewed, and was working great. here is a shot through the glove box opening

babyjames · #14 08-21-2009, 05:53 PM

In the bottom lefthand corner of the frame? Isn't that a vac line? Same color as the one that comes from the splitter under the bonnet? Follow him and start checking from there....

Jay

kerry · #15 08-21-2009, 06:14 PM

Quote:

Originally Posted by babyjames

In the bottom lefthand corner of the frame? Isn't that a vac line? Same color as the one that comes from the splitter under the bonnet? Follow him and start checking from there....

Jay

My thought precisely.