When soldering make sure you heat the wire up enough so the solder will flow across the wire and connection point.
Do not just apply solder to the end of the soldering iron without the wire being hot enough. This may give you a dry solder joint with poor conductivity and low strength. You need the solder to flow nicely .
Personally i think you may have problem with your soldering joint.
Have less wire exposed , if the cable gets pulled it may short out.
It should be physically strong and conductivity sound. Use plenty of solder. Watch out for solder drips onto other wiring , etc. I place a old cloth were solder may land.
This is important - & although said jokingly what I mean about keeping it short (so it doesn't short). It depends on the angle of the photo - I think top 1st go (& it's the event that's important) but would it be even better if the wire wasn't stripped so far??
