The bad solder joints is not the only issue with these RCM modules. Very often the contacts on the relays go bad. The coils can also go bad. Sometimes the relay would make audible click and even visibly make a contact but still not enough to properly conduct because the contact points are so bad. I have a refurbished RCM module for sale if you're interested PM me. I can't guarantee that's your source of issue but you can try. Worst case you'll have a spare RCM when yours go bad.