Steve,

I think I went through pretty much the same ordeal that you're experiencing now. The new aux pump helped but did not restore ACC operation to normal. The clicking noise (coupled with intermittent blower operation) seems to be caused by bad signals from the pushbutton unit to the associated relays. I managed to get a good used climate control unit from another 87 300D.

Another thing to note - according to MB the 1987 300D/TD pushbutton unit is specific to those models - and not interchangeable with other years. As far as the Programma units being any good or not, I'm really not sure. They do have a three year warranty though.

I have been having the same clicking. It took me 45mins of idle before I got the heat to work. Just installed a aux water pump today and the prob went away. I am curious though, if what you all say is true and the unit is bad will a climate control system out of a 300TE work?

__________________
Owen

87 300TD 603 I-6
94 Jeep XJ I-6 4.0 (see the pattern)
89 750il
seventy-two hundred feet above sea level (kinda cold up here)

I have a Programa unit - they have been a good experience so far. I thought my rebuilt programa unit had failed and I sent it in. They sent it back tested OK. I still thought it was still bad so I sent it back, they exchanged it for another rebuilt unit as a courtesy at no charge. That got my business and I have just sent in my cruise control amplifier for them to rebuild.

I had that clicking noise as well. I still had trouble determining if it was the Climate Control, the switchover valves or the blower regulator (or a combo) making the noise.

I've tried the ignition key wiggle and it doesn't seem to make a difference.

After doing a monovalve rebuild and installing new aux water pump, I still had my Climate Control switching off. I had to replace the center vacuum pod anyway (no a/c air through center vents) so I pulled the dash apart. I found the #1 and #3 switchover valves to be bad. I also replaced the Evaporator temp sensor and the other little sensor (to the heater?) that plugs in right behind the climate control (two-prong plug, about 3" long black prope) right below the light "octopus."

Replacing those sensors stopped the loud clicking and shut down of my Climate Control (shut down meaning when it clicked I could not get the unit or blower to respond).

The only problem I have at this point, is when I have the Econ or normal A/C button of the Climate Control depressed when I start the car - the climate control remains off (no blower control). If I punch the MAX button and then immediately back to the norm A/C or Econ button - the unit comes to life and does it's job perfectly and never shuts off..... weird huh.

__________________
~shell
As of 2/2010:
2001 CLK55 0o\=*=/o0
13.6 @ 106mph
10K mi
1984 300SD
260K mi and going and going...
97 S600
46K miles
1991 Sentra SE-R (extremely dorked with)
www.se-r.net

Thanks for all of the great responses. It looks like I will have to replace the control unit on ACC as well. I took a look at the Programa web site and it looks like they will repair/refurbish my unit if I send it in.

bodyart27, thanks for the insight on Programa. I will give them a try. I think the symptoms between our vehicles may have different causes since mine is a W124 and your is a W126. Thanks for the info though.

nuckingfuts, I believe the control unit for a 300TE is different than the unit for the 1987 300TD/300D according to the research I have done.

-Steve

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1987 300TDT smoke silver w/ burgundy leather interior
2000 VW Passat wagon indigo blue w/ beige leather interior
1985 Mustang SVO
1970 Chevrolet K10 fleetside, shortbed

I have anoying sound seems to be coming from under the dash possibly the climate control or the area around it.. It sounds like WaaaAAAAAA WaaaAAAAA etc. I thought it was the blower but I listened carefully and it was not the blower.
It only stops if I turn the acc unit off by pushing the button at the far right
marked with (O) . Any idea or help

My '87 is a 190DT, different animal, but same symptoms.

I had CC problems, replaced the pushbutton unit. The clicking started. I removed the pushbutton unit and opened it, one transistor had gotten hot. Chased the circuit around, and based on what I read on this forum, I found a seized/shorted aux. pump. I replaced the pump and all was well. The original shorted pump had destroyed the pushbutton unit.

- Jeff Miller
190DT

I think that's the sampler motor, which draws in air to test the temperature. I have read elsewhere that they occasionally need to be cleaned/lubricated or replaced.

i found a number of bad solder joints on my climate control push button unit 1987 300tdt.it was doing a whole lot of crazy things til i resoldered.