re: How to Repair Relay Control Module (RCM) - (Mystery no Start)
To do this properly you should remove all the solder that you can with de-soldering tape, clean the posts with a small file or fine emery paper and then re-solder.
These were dry joints when they were made because the post did not get hot enough to allow the solder to adhere to it. Vibration was not the problem as has been mentioned in the past.
Adding more solder to the joint will not really solve the issue as the post must be clean to allow the solder to physically adhere to it.
Use resin cored solder only or one that says it is for electronics, that solder you used for your copper plumbing is no good at all.