DIY page. Introduction to Resoldering Climate Control Unit - Page 2 - PeachParts Mercedes-Benz Forum

R Leo · #1 04-18-2004, 09:49 AM

Good write-up Jeff!

BoostnBenz · #2 04-21-2004, 12:52 AM

Thanks Randy.

Ever come to a conclusion Fisherman?

rhino · #3 04-21-2004, 02:41 PM

thanks.

Mine: only works after putting on defrost, then hi.
only works at max/min values.

You gave me two great ideas on fixing these!! Thanks a ton.

Fisherman · #4 04-22-2004, 03:02 PM

I had to run down to SF for some business. I've got a couple of versions that I will shoot pics of cuz they are all a little different. If you want I can email to you also...

jobaa · #5 07-20-2007, 03:02 PM

i have resoldered mine several times on several different cars. it's a common problem. i'm not so sure it's vibration that causes the problem though. it may be the component on the circuit board itself. some components get warm when in use. the warming and cooling will crack the solder joint. i repaired my mig welder that had the same problem. i've also repaired 2 of my t.v. sets, same thing. no vibration on the t.v.'s. just cracked joints from the heating and cooling of the individual component. with the expansion and contraction the solder gets work hardened and fails. much like bending a piece of metal back and forth until it breaks. that's my 2 cents. J.O.

pwogaman · #6 07-26-2007, 01:43 AM

Here is a picture of a bad solder joint before repair. It is the best resolution I could attain. The black ring surrounding the joint is an open crack visible with my 18X magnifying lense.

omegabenz · #7 07-25-2007, 06:12 PM

Jeff aka boostnbenz, you had mentioned that the switches can be purchased. Do you mean from like Mouser or something?

CA-Rick · #8 07-25-2007, 07:11 PM

I just removed the unit and have it totally disassembled. I think!?

Does the black plastic case which holds the boards come apart?

I think, from the thread, that I just solder the ones that look brown or loose. At first sight, everything is ok so I'm wondering if this will fix my CCU.(replaced my ignition switch because the CC goes off and on when it wants to.)

I'll solder what I think is bad and put it back together.
One more thing. The 'AUTO' button falls out. I don't really see anything holding it in except a small ridge on the bottom of the button?

omegabenz · #9 07-25-2007, 08:30 PM

Quote:

Originally Posted by CA-Rick

Does the black plastic case which holds the boards come apart?

Yes, It rotates out in relation to the switch buttons (push)

Quote:

Originally Posted by CA-Rick

I think, from the thread, that I just solder the ones that look brown or loose. At first sight, everything is ok so I'm wondering if this will fix my CCU.(replaced my ignition switch because the CC goes off and on when it wants to.)

solder them all, and expecially where the two boards meet. Brown is a good clue.

The button is black, it has a white inside with two tabs, are they broken or there. You can buy just the buttons from MB

AUTO BUTTON 123.153
A1268211758

CA-Rick · #10 07-25-2007, 10:07 PM

Thanks omegabenz, that helped me a lot.

Well, i put it back, or actually just connected the power to it and it seems fine. I'll see because this is what happens. First it will work and after 3-5 min. it will shut off for good.? Hopefully my solder job did the trick.

My other question is about the set of 5 lights connected together. I put the lights on and none work. I don't think that they did originally so I'm going to the Benz dealership to buy them. I have some lights with the white body only that looks like its own socket, plugged into two male electrical fittings? or ones that have that white fitting that sit in a black plastic male socket.

Either way, do they just 'pull' out or what? Do you think they will have them in stock?

mplafleur · #11 07-25-2007, 11:33 PM

When resoldering these old high current connections, I find it useful to use solder wick (a braided copper material) to remove as much as the old solder as possible, or a solder sucker. Then use new solder for the connection.

omegabenz · #12 07-26-2007, 01:36 AM

Quote:

Originally Posted by CA-Rick

My other question is about the set of 5 lights connected together. I put the lights on and none work. I don't think that they did originally so I'm going to the Benz dealership to buy them. I have some lights with the white body only that looks like its own socket, plugged into two male electrical fittings? or ones that have that white fitting that sit in a black plastic male socket.

SYLVANIA 2721 BULBS (I just got some at checker), you need at least 5 bulbs

BoostnBenz · #13 07-26-2007, 11:53 PM

Quote:

Originally Posted by omegabenz

Jeff aka boostnbenz, you had mentioned that the switches can be purchased. Do you mean from like Mouser or something?

Back when I wrote that a few years ago there were several online parts places which sold just the fan speed switches for the CCU, it was the white body with everything inside of it. I don't recall if they had the temperature control knob available separately or not.

omegabenz · #14 07-27-2007, 04:39 AM

Quote:

Originally Posted by BoostnBenz

Back when I wrote that a few years ago there were several online parts places which sold just the fan speed switches for the CCU, it was the white body with everything inside of it. I don't recall if they had the temperature control knob available separately or not.

They are available here on mercedesshop as well.

I resoldered the board twice, and examined it, but I am still haveing problems. I took everything apart and cleaned it, etc.

for the w124.133 board, its working great now, but for my w123.153 I cant seem to get the climate control to work properly. Should I check anything else?

BoostnBenz · #15 07-28-2007, 01:00 AM

Did you resolder the pins where the side harnesses connect to?