123 CCU Removal - PeachParts Mercedes-Benz Forum

JEREMYC · #1 08-28-2006, 10:40 AM

Can anyone tell me the correct way to remove the CCU from a 123 chassis? I already have the wood off of the CCU face for refinishing. I removed my radio yesterday and installed an aftermarket radio but I could not figure out how to remove the CCU unit. It looked like there were two metal tabs at the bottom of the unit sticking out but they wouldnt move. Are there screws in the bottom of it that can be accessed once the radio is out? Did a search on this one too, no help there. Maybe I need to loearn how to better use the search function. I also checked the DIY articles and it covers pulling everything but the CCU. Thanks!

Jeremy5848 · #2 08-28-2006, 10:47 AM

1. Remove two flat-head Phillips screws from upper corners.

2. Lift CCU until tabs at lower corners release. This can be difficult, be careful. I found it best to insert a flat-bladed screwdriver in one of the slots in the plastic face and lift while pulling out slightly to gain clearance at the top. Try to 'pop' the tab on one side and then the other. Go slow, be careful. It will come free. Why they didn't just use 4 screws I don't know (parts count?).

3. Once the CCU is loose, unplug the big connectors at left and right. Then undo the string of light bulbs and the CCU is free.

Jeremy (Sr.)

JEREMYC · #3 08-28-2006, 10:51 AM

I did not see any flat head screws. I took the wood off (was loose already) and the metal plate is still there. Does the metal plate need to come off to get to the screws?

Jeremy5848 · #4 08-28-2006, 10:53 AM

Ah so! The wood is supposed to stick to the metal plate. Use contact cement.

The metal plate has four snaps that hold it to the plastic. It just pops off. Pry gently with fingers or a screwdriver. The fun stuff is underneath.

JEREMYC · #5 08-28-2006, 10:58 AM

You da Man! Thanks. BTW....great name!

JEREMYC · #6 08-28-2006, 11:07 AM

Actually, the reason I ask all of this is because my CCU is not working today at all after doing the aftermarket radio install yesterday. I was looking for a constant hot wire and was using the test light in the fuse box, well I accidentaly touched the metal part of the test light that was on a constant hot to another fuse socket that was only hot when key is one. I didnt see any sparks or anything and it may have done nothing at all. I think all that would do is give power to something without using the key to do it. I think the problem is because I also moved all my fuses to where the metal part of the fuse faces up and I found one fuse that broke when I barely touched it. Since I have no power at all to the CCU, I probably have a busted fuse somewhere. I just havent had time to check it yet.