Originally Posted by
Robertwav1
Just for your information. Some 10 years ago or so the solder connections went bad on the RCM. Well, fixed them at that time and just out of nowhere the car quit, wouldn't start, waited a while and got the car home. My first thought was the RCM again but how could it be that, I've already addressed it years ago? Well it was, joints were poor again under a glass. Guess I should have done the Mod at the time but figured, no big deal, the re-solder should be fine. Mind you, it's been 10 years ago and it held up fine to this point. I'm one of those that keeps vehicles forever. Anyway, redid them again and problem solved once again. I guess it's a hot spot on this board and that's why the mod should be done to eliminate this problem. Thought I'd reach out and let people know in case they already fixed this and it came back.....it did take a long time though.
I can see no reason for a good solder job to fail, the terminals must be cleaned prior to resoldering and sufficient heat applied to avoid a cold joint. The use of acid flux or acid cored solder will cause future failures as well, only use resin cored solder for electronics.
Some say vibration is the culprit and that is not true.
Poor soldering caused the failure on the original RCMs.
Burnt contacts are the cause of many relays to fail, if they get burnt replace the relay ASAP.