Mercedes-Benz Forum banner
1 - 9 of 9 Posts

·
Registered
1990 420sel
Joined
·
324 Posts
Discussion Starter · #1 ·
What else can be done in addition to resoldering the joints on the Climate Control Unit? My Defrost won't stay on without holding the button down. The real problem in addition to this is that my A/C compressor won't turn on. MB dealership diagnosed the unit to be faulty.

I'd like to try to rebuild before buying a reman'd unit.

Thanks in advance,

Chris
 

·
CH4S Admin , Outstanding Contributor
1985 500SEC, 1991 190E 2.6.
Joined
·
45,347 Posts
Any junkyards / MB dismantlers in your area? Some sell a warranty for a few extra $.
 

·
Registered
1990 420sel
Joined
·
324 Posts
Discussion Starter · #3 ·
I may try calling my local junkyards..but there aren't too many SEL's in my area so my chances won't be that great. I found used one in AZ for $150 with a 30 day warranty. That's a bit of a gamble, since for $100 more I can have a rebuilt unit.
 

·
Registered
1983 Euro 500SEC AMG, 83 SEC custom convertible, 2x 84 500SEC, 02 w203coupe, euro 1985 300d
Joined
·
1,579 Posts
i have found it is cheaper to work more hours at one's job and buying these used/new then messing with sauldering of these electronics-----case in point

I had an electronics engineer friend of mine go over the idle control box (you know the one you have to squeeze to work correctly) and he was able to fix 3 out of thew 5 i gave him--after souldering the boards and connections he said it would be better to buy the reman ones than the individual components and testing each one for consistency----just my 2c

but if you don't have the funds, im sure someone will have one for cheap sooner then later
 

·
Registered
1990 420sel
Joined
·
324 Posts
Discussion Starter · #5 ·
I went ahead and bought a reman'd unit from Autohaus. I got to thinking that I don't want to get put in the same situation I was in where I couldn't figure out why the compressor was not turning on (or other weird issues). I just spent $270 at the dealer to diagnose my problem, and if I end up with a bad used CCU I may end up back again in a couple of years.

I was feeling confident after successfully repairing my cruise control amp, but the ccu had much smaller joints, and looked much easier to screw up.
 

·
Registered
1988 Mercedes 300SE
Joined
·
61 Posts
Well, I got the cruise control amp out of my hoopty last night, and slid the circuit board out of the box. No obviously smoked parts. Considering hacking away at it with my soldering iron. RPH74; any tactics, techniques or procedures you could recommend before I fry this box the rest of the way?
 

·
Premium Member
1983 380SEC: 1995 S600 Coupe: 1993 600SEL
Joined
·
377 Posts
Cruise amp

bigdon said:
Well, I got the cruise control amp out of my hoopty last night, and slid the circuit board out of the box. No obviously smoked parts. Considering hacking away at it with my soldering iron. RPH74; any tactics, techniques or procedures you could recommend before I fry this box the rest of the way?
I just did mine a couple of hours ago. I started to resolder the joints and had a little bit of trouble getting the connections to melt right away. So I used brake clean to get all of the resin off of the board from the manufacturer. Dried it real well with compressed air. I used a butane soldering iron I got from the Snap-On truck. I also used .022" silver bearing solder from Radio Shack. With all the resin gone, it only took about 1 second for the solder on the board to melt and add the new solder. Took about 15 minutes after the board was cleaned.

Hope this helps.

Pete
 

·
Registered
1990 420sel
Joined
·
324 Posts
Discussion Starter · #8 ·
bigdon said:
Well, I got the cruise control amp out of my hoopty last night, and slid the circuit board out of the box. No obviously smoked parts. Considering hacking away at it with my soldering iron. RPH74; any tactics, techniques or procedures you could recommend before I fry this box the rest of the way?
Make sure you don't bridge any joints that weren't meant to be bridged (ie melting 2 joints into one). I accidentally did this twice, but I was able to separate it by melting in the middle and moving the solder back. There's really no trick to it. It was my first time ever using a soldering iron, so I first worked on the biggest joints, which were the ones in a straight line closest to where you plug in the cruise control amp. Keep the iron steady until you see the "ripple" effect. I didn't use any solder at all, just remelted all of the joints. You'll find that some joints will melt very quickly, and some will require you to press down hard with the iron.

I also slipped with the iron several times in the beginning, which scratched up the board quite a bit, yet it still works like a charm.
 

·
Premium Member
1990 SEC
Joined
·
4,289 Posts
For remanufactured ACC pushpanels, check out George Murphy's shop Performance Analysis:

Performance Analysis Co.
1345 Oak Ridge Turnpike, Suite 258
Oak Ridge, TN 37830
865-482-9175
[email protected]

He sells remanufactured ACC panels and a whole lot of other MB parts as well.

George is a MBCA technical director and guru. I went to hear him talk at a local MBCA event a couple of years ago and he was very impressive.
 
1 - 9 of 9 Posts
Top