My car died on me twice while driving. Then I parked it came back and it hasn't turned on since. There is no crank at all when I try to start the car. Dash lights all come on. I extracted my rcm. Here are some pics.. Do you think my solder points are broken?

 

Here is another pic

 

DJ,

That is practically free!

Thanks for all your electronic insights on this board

 

Not sure if you were being facetious or not, but that is definitely your problem!

 

The cracks have started even after 7 years and only 17,000 miles.

 

I went to autozone and picked up a soldering iron for $8 and thought I could do this myself since it looked easy enough. I have never soldered anything before.. This is the outcome...😩😤😭 ..... My car is still dead... HELP !!!

 

Another pitiful pic

 

Looks like you're not getting hot enough. Lay the iron on the base of the pins until all the old solder liquefies then add some new to the pins.

Or send it to DJ for $20 he will fix it.

Or get a new one from rock auto for $145.

 

Sure hope he used rosin-core solder, as it MIGHT be salvageable. Your not letting the iron get hot enough, which in turn isn't getting the places you wish to 'reflow' hot enough. Then there is the problem of getting it TOO hot. There is a fine line, hot enough AND not too hot. Times like these, you should not be 'practicing' on your RCM module. After you either send it to DJ (or) buy a replacement, you should then leave soldering to someone else until you can flow the solder properly.

 

Who's dj???? The guy that posted this thread? If so I did already message him 2 days ago. No response yet 😐

 

Two days on a weekend is not a long time.

"Send an email with your address to:
tighed1@hotmail.com"

It will take a week or two to get it shipped, repaired, and returned anyway.

If you need instant service, I suggest you buy a new one online and ship it next day air.

 

The boards were soldered in a bath of molten solder and the temperature of the pins was too cold as a result the solder did not bond properly to the pins. This is known as a cold joint.

As time and usage progress the joint weakens even more until arcing makes it fail completely.
The solder needs to be removed as much as possible from the joint, the pins cleaned to bare metal, and re soldered with rosin cored solder only, do not use acid cored solder.

This problem was written about before the Crossfire hit the market on the MB forums.
The seat relay was known to suffer from the same problem.

 

DJ, I sent you a email about fixing my RCM's
Thank you so much for providing this service,
will be nice to have confidence that after the
fix, that my car will start when I am out and
about.

 

I suspect the $8 soldering iron does not have enough wattage to heat those big pins. Here is a video showing how solder flows with the correct temperature (wattage) iron. In our case we need way more heat than the samples in this video.


https://www.youtube.com/watch?featur...JxytERvg#t=146

This video should start at the 2:25 mark.


Simular workflow except in our case the pins are bigger and there is already solder there, we just need to heat it till it flows back around the pin while adding a little more solder.

 

Has anyone ever noticed the schematic shows 5 15A fuses and the one 40A maxi but mine and all the pictures I find shows them with one yellow 20A plugged in. Anyone know why?

 

Yes, it is because the schematic is for the SLK230, MB#545 02 05. That's if the schematic you refer to is the one below.

SLK230 MB#545 02 05
SLK320, SLK32 & Crossfire MB#545 03 05

 

Nope, it's the PDF downloaded here. 4348 pages long. Pages 1673 & 1674, all show 15A.

 

That manual should not be taken as being written in stone. It was made up using MB manuals and was copied erroniously in many places.
If you look at the actual parts then you can see that the CF RCM uses theg larger fuse, at least in the ones I have seen.

 

This PDF looks nothing like the pics you posted so I don't think it's a copy. You have it, right? The one posted here.

 

I think you have misunderstood me, forget it as it is too hard to go through it all and straighten it out.