CCU Removal W126

[cbeaner007]

I am planning to remove the CCU from my '81 300SD. I have searched and read the posts on resoldering the unit, but cannot find advice on removal of the unit itself. Does the radio need to come out? If so how does one remove a Becker unit. The wood trim appears to be firmly adhered to the control unit itself and I really don't want to damage it as it is in really good shape. Thanks in advance.

CW

[rhodes2010]

Surprised there is not a how to on this.

I cannot imagine getting the CCU out without pulling the center console.
Which is really not that difficult, just an extra job to do.

The radio (Becker) , if I remember last time I did this,
was faceplate/trim off then tools on sides to release it.
Much like any replacement stereo.

I usually do pull the radio before console, then CCU.

[sixto]

IIRC, and it's been a really long time, you remove the ashtray to remove the radio. There are two screws in the radio cavity holding the wood trim around the CCU.

There are blade tools that slip into slots in the radio faceplate to release the radio -

http://cgi.ebay.com/ebaymotors/190543140924?

Harbor Freight used to sell a set but I don't see it in their online catalog anymore. Any car stereo installation shop should be able to help you or get creative with some band saw blades.

Sixto
87 300D

[rsmartin]

1. open ashtray
2. remove ashtray insert
3. remove two screws holding the ashtray frame to the console
4. unplug electric connections or let it hang out of the way
5. remove radio... if it is an original becker is slides out but there are two metal spring clip things on the bottom side to the front of each side of the radio that you pull down slight to release the radio.. then you should be able to slide it out pretty easily. i find it easier to push the radio out from the back while holding the metal clips down. takes three hands
6. once the radio is out, you can see two small screws hold to plastic tabs of on the bottom of the wooden piece that covers the CCU
7. the CCU is held in place by two screws on each side pinching the little bladed holders on the CCU


i know this is really dumb ass instructions but hopefully enough hints to help. it's not hard, but just go slow and look until you understand. once you do it once it only takes a few minutes to do it the next time, as always!

[cbeaner007]

Thanks guys! Worked like a charm. Resoldered all the connections and every button works as it should. Also cleaned all the relays with electrical cleaner and even the temperature wheel works again. Thanks again!

CW

[dave_zook@hyper]

Hi, I have an 85 SD. The climate control seems to work on its own without paying attention to the buttons. Most of the time it doesn't work at all. When it does, hot air enters the car but is not blown. The defroster works. Sometimes, though it happens less often, the unit will work if the off button is engaged before I start the motor. But it will only heat. The temperature wheel doesn't seem to matter at all.

Until the ccu started acting up, the ac worked like a charm with very cold air.

I was thinking that I needed to replace/resolder the ccu but I want to make sure that I am on the right track and there isn't another problem. This forum is most helpful but it can also cause me some confusion.

Any ideas?

Thanks,

Dave

[toomany MBZ]

Your unit is getting electrical signals it shouldn't, examine an electrical fix.

[dave_zook@hyper]

Where do I start looking for an electrical problem? I don't know much about all that. I certainly appreciate your help.

Dave

[toomany MBZ]

The thread discusses how to remove the ACC unit itself and there is a testimonial for reflowing the solder points, That's my suggestion.

[Junkman]

I have my 85SD CCU on the bench. There appear to be 2 boards that need to be un-soldered to get to all of the circuits. Buttons are press fit & can be popped off.

FWIW, youtube has video on removing CCU from a 126. "mercedes console" or some variation will find it.