Mercedes Solder problems??
 

Hello all,
I know I've gotten myself in hot water on this forum in the past for my somewhat biased comments, but here I go with another speculative thought! What's the deal with the poor solder that Mercedes seems to use?? From what I've seen on my '82 123 chassis, there's nothing wrong with the design of the electronics, but the soldered connections just don't hang together over time. It seems to be a problem with the type of solder that was used - it is brittle, or crumbly, not at all like the solder I am familiar with here in the US. In the Electronics industry here, we have always used a 60-40 lead/tin alloy solder, and the joints made with this solder hold up for 50 years or more with no problems. The Mercedes joints, for instance the joints in the Tach Amplifier on my 123 and the heater control unit suffer from what appears to be metal fatigue, and fail prematurely. Was there a shortage of lead or tin that caused Mercedes to use an inferior product, or is there some regulation regarding one of these metals in Germany? I suspect that the soldered joints cause most of the strangely intermittent problems that people have trouble identifying but that drive a person up the wall. What do others think on this issue??

Regards,
Richard Wooldridge
'82 300D/4.3L V6
Etc...

Yes you are right there does seem to be a problem with the quality of the solder.

My advice would be to use a non MB battery as they have less aggresive amps than those from the genuine article. The more aggresive amps while more effective, do lead to solder fatigue.

You may have seen the discussion @ http://www.peachparts.com/shopforum/tech-help/52623-i-used-battery-snob.html

Credit to Cap'n for postulating this hitherto little known theory!