Hi All,
I am trying to get my CC fully operational again and I'd like some help.

So far I have replaced every single vacuum module (for flaps operation etc.)

I have replaced the original dual switchover valve set-up with the new single unit from MB.

I have replaced the original pushbutton unit with a rebuilt.

I have replaced the potentiometer on top of the heater box with a new one from MB.


I have bought one of the 12V Leds to use as a tester.

Right now the car has the dash completely stripped out for access to all the components (the instrument cluster is connected so I can see whats going on).

What happens now is that the defroster nozzles won't close on any setting. I can get heat, but only full heat. I can get a/c any time I want.

I can operate all of the vacuum units fully with a mity-vac. All of them will hold a vacuum indefinitely.


I know that I can connect the LED to the connectors on the PB unit to get a code readout but am unsure about how to do that. Can anyone help. At this stage I have large amounts of $$ in parts and so would really really like to succeed in getting this going.

Any results will be posted here so that future members can get it from the archives!


Thanks in advance.

Jim

Jim,
What year car? The system changed 3 times durning it's production run. There are different feedback readings dependant on model years. & different part number controllers as well.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

The car is a 1989, originally sold in CA and maintained on the Mercedes lease fleet.

Sorry about that. I can't believe that I forgot the year!

Jim

PLEASE MILLTEK, The pushbuttons of the Climate Control on my

190E, 2.6, 1988 are failing. Where can I get a rebuilder one

pushbutton switch.

Thanks.

MARIO FARIAS
laprefar@cantv

__________________
MB LOVER

Guys,
I'd really appreciate some help with this issue. The car has been in pieces for two weeks now and I'd really like to solve this problem.

Jim

Jim,
I have a '91 190e 2.6 and went through the same thing a few months ago.

After replacing some of the vacuum actuators and the potentiometer like you did everything was holding a good vacuum. The switchover valve was also operating correctly.

However, things still weren't working and I discovered that one of those little rubber elbows that connects vacuum lines was cracked. Check all of yours.

Vacuum supply starts at the intake manifold then runs to a check valve then to a container in the right fender. The vacuum then runs to the vacuum switchover unit which is right behind the rightside vent behind the dash.

I know the system changed alot over the years but that's how mine was set up. Hope this helps.

Bruce

bdlefferts,

Were you experiencing exactly the same symptoms that milltek and I are -- no heat to floor and max. heat to windshield? Also, do you remember approximately where within the overall system the rubber connector was located?

Ed

Bump.

Really need some guidance on how to check the pulse codes in my pushbutton control unit using the LED.

Thanks,

Jim